<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中，自增和自减运算符是用于增加或减少变量的值。这些运算符包括<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">++</code>（自增）和<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">--</code>（自减）。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">自增运算符<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">++</code>可以在一个变量的末尾添加一个值。这意味着使用自增运算符将增加变量的值1。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">5</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">a++; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 等价于 a = a + 1; </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(a); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 6</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的初始值为5，然后使用自增运算符<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">++</code>将其值增加1，并将结果赋值给<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>。最后，通过打印<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的值，我们可以看到<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的新值为6。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">自减运算符<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">--</code>与自增运算符相反，它可以在一个变量的末尾减去一个值。这意味着使用自减运算符将减少变量的值1。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">10</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">b--; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 等价于 b = b - 1; </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(b); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 9</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的初始值为10，然后使用自减运算符<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">--</code>将其值减少1，并将结果赋值给<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>。最后，通过打印<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的值，我们可以看到<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的新值为9。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">除了整数之外，自增和自减运算符也可以用于浮点数类型。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">c</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3.5</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">c++; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 等价于 c = c + 1.0; </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(c); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 4.5</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">c</code>的初始值为3.5，然后使用自增运算符<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">++</code>将其值增加1.0，并将结果赋值给<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">c</code>。最后，通过打印<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">c</code>的值，我们可以看到<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">c</code>的新值为4.5。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">自增和自减运算符是Java中的算术运算符，用于增加或减少变量的值。这些运算符可以简化代码并提高可读性。</p><p><br/></p>
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<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中，算术运算符相除和取模用于执行除法和取模运算。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">首先，让我们来介绍相除运算符。相除运算符使用斜杠（/）表示，它用于执行除法运算。在Java中，整数除法会截断小数部分并返回整数结果。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">7</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">result</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> a / b; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 结果为 2，因为 7 除以 3 等于 2.3333，但整数除法只保留整数部分 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(result); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 2</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的值为7，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的值为3。使用相除运算符将<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>除以<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>，得到的结果为2。这是因为在整数除法中，小数部分会被截断，只保留整数部分。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">接下来，让我们来介绍取模运算符。取模运算符使用百分号（%）表示，它用于计算除法的余数。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">7</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">remainder</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> a % b; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 结果为 1，因为 7 除以 3 的余数是 1 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(remainder); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 1</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的值为7，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的值为3。使用取模运算符将<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>除以<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的余数计算出来，得到的结果为1。这是因为7除以3的余数是1。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">需要注意的是，当使用浮点数进行除法和取模运算时，结果将是浮点数。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">7.0</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3.0</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">result</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> a / b; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 结果为 2.3333333333333335 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(result); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 2.3333333333333335</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的值为7.0，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的值为3.0。使用相除运算符将<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>除以<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>，得到的结果为2.3333333333333335。这是因为在浮点数除法中，小数部分会被保留。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中，加法运算符（加号+）用于对两个数值进行加法运算。下面是一个简单的示例：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">5</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">sum</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> a + b; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 结果为 8，因为 5 + 3 = 8 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(sum); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 8</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的值为5，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的值为3。使用加法运算符将<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>和<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>相加，得到的结果为8。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">除了整数之外，加法运算符也可以用于浮点数类型。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">2.5</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3.7</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">sum</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> a + b; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 结果为 6.2，因为 2.5 + 3.7 = 6.2 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(sum); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 6.2</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>的值为2.5，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>的值为3.7。使用加法运算符将<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>和<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>相加，得到的结果为6.2。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">除了基本的加法运算之外，Java中的加法运算符还可以用于字符串连接。当一个操作数是字符串类型而另一个操作数是数值类型时，Java会自动将数值类型转换为字符串类型，并将两个字符串连接起来。例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">String</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"Hello"</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">String</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">result</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> a + b; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 结果为 "Hello3"，因为 "Hello" + 3 的结果是 "Hello3" </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(result); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 输出结果为 "Hello3"</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上面的示例中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>是字符串类型，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>是整型。使用加法运算符将<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">a</code>和<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">b</code>连接起来，得到的结果为"Hello3"。这是因为Java将整型数值3转换为字符串类型，然后将其与"Hello"连接起来。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中，<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Scanner</code>类是用于从各种输入源获取输入的类。它通常用于获取用户的键盘输入，但也可以用于读取文件、网络套接字和其他输入源。以下是如何使用<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Scanner</code>类从键盘获取输入的示例：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">import</span> java.util.Scanner; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 导入 Scanner 类 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">public</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">class</span> <span class="hljs-title class_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">Main</span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">public</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">static</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">void</span> <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">main</span><span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">(String[] args)</span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">Scanner</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">input</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">new</span> <span class="hljs-title class_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">Scanner</span>(System.in); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 创建 Scanner 对象 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"请输入一个整数:"</span>);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">number</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> input.nextInt(); <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 读取用户输入的整数 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"您输入的整数是 "</span> + number);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">}</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">}</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个例子中，我们首先导入了<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">java.util.Scanner</code>包。然后，在<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">main</code>方法中，我们创建了一个<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Scanner</code>对象，并将其连接到<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">System.in</code>，这是Java的标准输入流。然后，我们使用<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">nextInt()</code>方法从输入流中读取一个整数。这个方法将阻塞，直到用户在键盘上输入一个整数，并按下回车键。然后我们将读取的整数打印出来。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;"><code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Scanner</code>类有很多方法可以获取不同类型的数据，例如：</p><ul style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p><code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">nextInt()</code>：读取下一个输入的整数。</p></li><li><p><code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">nextDouble()</code>：读取下一个输入的双精度浮点数。</p></li><li><p><code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">nextLine()</code>：读取并返回用户输入的下一行，直到用户按下回车键。</p></li><li><p><code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">next()</code>：读取并返回用户输入的下一个词。</p></li></ul><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">需要注意的是，当使用<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Scanner</code>类读取数据时，应该始终检查是否有数据可供读取，否则在尝试读取数据时可能会出现异常。例如，如果用户输入的是一个字符串而不是整数，那么<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">nextInt()</code>方法将抛出<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">InputMismatchException</code>异常。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中，强制数据类型转换是一种在编译时期需要明确数据类型转换的方法。这与自动数据类型转换不同，自动数据类型转换是在编译时期自动进行的。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">强制类型转换的基本语法如下：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">type</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">variableName</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> (type) value;</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这里，<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">type</code>是你希望将值转换为的数据类型，<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">value</code>是你要转换的值。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">例如，假设你有一个<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">double</code>值，你想将其转换为<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">int</code>，你可以这样做：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">d</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">100.0</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">i</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> (<span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span>) d; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 强制类型转换</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个例子中，变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">i</code>的值将会是100，尽管原始的<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">double</code>值是100.0。注意，在强制类型转换时，小数部分会被截断。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">再例如，如果你有一个<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">String</code>，你想将其转换为<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">int</code>，你可以这样做：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">String</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">s</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"123"</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">i</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> (<span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span>) s; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 强制类型转换</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在这个例子中，字符串"123"被强制转换为整数123。如果字符串不能被解析为有效的整数，那么会抛出<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">NumberFormatException</code>。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">需要注意的是，不是所有的数据类型都可以进行强制转换。只有那些有明确的转换规则的数据类型（如<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">int</code>，<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">float</code>，<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">double</code>等）才可以进行强制转换。例如，你不能将一个<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Object</code>强制转换为一个<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">int</code>。此外，在进行强制类型转换时，必须注意数据类型的范围和可能出现的异常。</p><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">Java中存在一种称为自动数据类型转换（Autoboxing and Unboxing）的特性，它允许开发者在需要时自动转换基本数据类型和对应的包装类。这种特性在Java 5.0中被引入，使得代码更加简洁易读。</p><h3 style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin: 0px; color: rgba(0, 0, 0, 0.85); font-size: 18px; border: none; line-height: 1.75; text-wrap: wrap;">自动装箱（Autoboxing）</h3><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">自动装箱是指将基本数据类型自动转换为对应的包装类。Java提供了一组对应的包装类，如Integer、Double等，它们可以与基本类型自动转换。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">例如，当我们试图将一个int值赋值给一个Integer对象时，Java编译器会自动将其转换：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">i</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">10</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">Integer</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">j</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> i; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 自动装箱，实际是 Integer j = Integer.valueOf(i);</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">类似的，其他基本类型如boolean、float、char等也可以自动装箱为对应的包装类Boolean、Float和Character。</p><h3 style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin: 0px; color: rgba(0, 0, 0, 0.85); font-size: 18px; border: none; line-height: 1.75; text-wrap: wrap;">自动拆箱（Unboxing）</h3><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">自动拆箱是指将包装类自动转换为对应的基本数据类型。通过调用包装类的valueOf方法，Java可以自动进行拆箱操作。</p><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">例如，当我们试图从Integer对象获取其int值时，Java编译器会自动将其转换：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">Integer</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">i</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">10</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">j</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> i; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 自动拆箱，实际是 int j = i.intValue();</span></td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">类似的，其他包装类如Boolean、Float和Character也可以自动拆箱为对应的boolean、float和char。</p><h3 style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin: 0px; color: rgba(0, 0, 0, 0.85); font-size: 18px; border: none; line-height: 1.75; text-wrap: wrap;">注意事项</h3><ul style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>自动转换不会发生在非对应类型的转换中，例如不能将int自动转换为double。此时需要显式转换。</p></li><li><p>自动转换可能会导致精度损失，例如将double自动转换为int时会截断小数部分。</p></li><li><p>自动转换不适用于所有的操作，例如在算术运算符中，自动转换只在两个操作数都是同一类型时才会发生。</p></li><li><p>自动转换并不总是最优选择。在某些情况下，显式转换可能会更清晰易读。</p></li></ul><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中，常量是指在程序运行期间不会发生改变的值。Java提供了几种类型的常量，包括字面常量、常量变量和符号常量。下面是一些关于Java常量的示例代码：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>字面常量</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">字面常量是直接在代码中给出的常量值，例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">a</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">10</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 整型字面常量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">float</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">b</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3.14f</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 浮点型字面常量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">boolean</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">c</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-literal" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">true</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 布尔型字面常量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">char</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">d</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'A'</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 字符型字面常量</span></td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>常量变量</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">常量变量是通过关键字<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">final</code>声明的变量，它只能被赋值一次，例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">final</span> <span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">e</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">20</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 常量变量e的值为20，不能被修改 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">e = <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">30</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 编译器会报错，因为e是常量变量</span></td></tr></tbody></table></code></pre><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>符号常量</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">符号常量是用关键字<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">static</code>和<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">final</code>声明的常量，它可以在程序的所有实例中被共享，例如：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">public</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">class</span> <span class="hljs-title class_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">MyClass</span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">public</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">static</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">final</span> <span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">FOO</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">10</span>; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 符号常量FOO的值为10，不能被修改 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">}</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上述代码中，我们定义了一个名为<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">FOO</code>的符号常量，它的值为10。由于它是静态的，因此可以在程序的所有实例中被共享。由于它是final的，因此不能被修改。我们可以通过以下方式使用它：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">foo</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> MyClass.FOO; <span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 使用符号常量FOO</span></td></tr></tbody></table></code></pre><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在Java中定义变量时，需要注意以下几点：</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>变量名：变量名必须符合Java的命名规则，即必须以字母、下划线或美元符号开头，后面可以跟着字母、数字或下划线。变量名是区分大小写的，因此变量<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">age</code>和<code class=" inline" style="box-sizing: border-box; padding: 1px 4px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px 2px; font-size: 12.75px; tab-size: 4; background-color: rgba(27, 31, 35, 0.05); border-radius: 3px;">Age</code>是两个不同的变量。</p></li><li><p>数据类型：在定义变量时，必须指定变量的数据类型。Java支持的数据类型包括整数类型（如int）、浮点类型（如float和double）、字符类型（如char）、布尔类型（如boolean）等。</p></li><li><p>赋值：变量定义后，必须对其进行赋值才能使用。未赋值的变量会被赋予默认值，具体取决于其数据类型。例如，整数类型的变量未赋值时会被赋值为0，布尔类型的变量未赋值时会被赋值为false。</p></li><li><p>声明位置：变量的声明通常放在代码的顶部，也可以放在方法或构造函数的内部。但是，如果变量是局部变量（即定义在方法或构造函数内部），则只能在定义它的方法或构造函数中使用。</p></li><li><p>访问修饰符：Java提供了访问修饰符来控制变量的可见性。public、protected和default（没有修饰符）都可以用来声明类的成员变量，而private可以用来声明私有变量。public和protected变量可以在其所在的类和其他类中访问，default变量可以在其所在的类中访问，而private变量只能在所在的类中访问。</p></li><li><p>作用域：变量的作用域指的是变量的可见性范围。在Java中，变量的作用域可以是局部的或全局的。局部变量是指在方法或构造函数内部定义的变量，只能在其所在的代码块中访问。全局变量是指在类中定义的变量，可以在整个类中访问。</p></li><li><p>初始值：如果定义变量时没有指定初始值，则Java会根据变量的类型自动为其赋一个初始值。例如，整数类型的变量会被赋值为0，布尔类型的变量会被赋值为false，字符类型的变量会被赋值为null字符，浮点类型的变量会被赋值为0.0。</p></li></ol><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">以下是一个简单的Java程序，演示了变量的定义和使用：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-java" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">public</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">class</span> <span class="hljs-title class_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">MyProgram</span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">public</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">static</span> <span class="hljs-keyword" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(121, 40, 161); line-height: 24px;">void</span> <span class="hljs-title function_" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(0, 127, 170); line-height: 24px;">main</span><span class="hljs-params" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">(String[] args)</span> {</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义整数类型的变量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">int</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">myInt</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">10</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义浮点类型的变量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">float</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">myFloat</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">3.14f</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义布尔类型的变量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">boolean</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">myBool</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-literal" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">true</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义字符类型的变量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">char</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">myChar</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">'A'</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 定义双精度浮点类型的变量 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-type" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">double</span> <span class="hljs-variable" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(217, 30, 24); line-height: 24px;">myDouble</span> <span class="hljs-operator" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">=</span> <span class="hljs-number" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(170, 93, 0); line-height: 24px;">2.5</span>;</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><br/></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><span class="hljs-comment" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: rgb(105, 105, 105); line-height: 24px;">// 打印变量的值 </span></td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"myInt = "</span> + myInt);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"myFloat = "</span> + myFloat);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"myBool = "</span> + myBool);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"myChar = "</span> + myChar);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">System.out.println(<span class="hljs-string" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; color: green; line-height: 24px;">"myDouble = "</span> + myDouble);</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">}</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">}</td></tr></tbody></table></code></pre><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">在上述代码中，我们定义了五个不同类型的变量：整数类型（int）、浮点类型（float）、布尔类型（boolean）、字符类型（char）和双精度浮点类型（double）。每个变量都有一个名称（例如myInt、myFloat等）和一个类型（例如int、float等），并且每个变量都有一个初始值。在本例中，我们为每个变量赋了一个初始值，然后使用System.out.println()语句将它们的值打印到控制台上。输出结果如下：</p><pre style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin-top: 14px; margin-bottom: 0px; font-size: 15px; overflow: auto; border-radius: 6px; color: rgb(5, 7, 59);"><code class="language-" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier, monospace; margin: 0px; font-size: 1em; tab-size: 4;"><table class="hljs hljs-ln"><tbody style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;" class="firstRow"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">myInt = 10</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">myFloat = 3.14</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">myBool = true</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">myChar = A</td></tr><tr style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;"><td class="hljs-ln-line hljs-ln-numbers" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px; color: rgb(190, 191, 208); letter-spacing: 0px; max-width: 50px; overflow: hidden; text-align: justify; user-select: none; vertical-align: top; white-space-collapse: collapse;" width="30"><br/></td><td class="hljs-ln-line hljs-ln-code" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; margin: 0px; line-height: 24px;">myDouble = 2.5</td></tr></tbody></table></code></pre><p><br/></p>
<p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 0px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">Java是一种强类型语言，每个变量都必须先定义其数据类型。Java的数据类型可以分为两类：基本数据类型和引用数据类型。</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>基本数据类型</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">基本数据类型是Java语言中预先定义好的数据类型，包括以下几种：</p><ul style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>整型（int）：用于表示整数，取值范围为-2147483648到2147483647。</p></li><li><p>短整型（short）：用于表示短整数，取值范围为-32768到32767。</p></li><li><p>长整型（long）：用于表示长整数，取值范围为-9223372036854775808到9223372036854775807。</p></li><li><p>字符型（char）：用于表示一个字符，取值范围为'\u0000'到'\uffff'。</p></li><li><p>布尔型（boolean）：用于表示真或假，只能取true或false两个值。</p></li><li><p>浮点型（float）：用于表示单精度浮点数，取值范围为1.4E-45到3.4E+38。</p></li><li><p>双精度浮点型（double）：用于表示双精度浮点数，取值范围为2.2E-308到1.8E+308。</p></li></ul><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">除了以上几种基本数据类型外，Java还提供了其他几种数据类型，如定点数类型（BigDecimal）和日期时间类型（java.util.Date、java.time.LocalDate等），但这些类型通常在实际开发中使用的较少。</p><ol style="box-sizing: border-box; padding: 0px 0px 0px 32px; -webkit-font-smoothing: antialiased; list-style-position: outside; list-style-image: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 1em; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;" class=" list-paddingleft-2"><li><p>引用数据类型</p></li></ol><p class="" style="box-sizing: border-box; padding: 0px; -webkit-font-smoothing: antialiased; list-style: none; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, "Helvetica Neue", Helvetica, Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei UI", "Microsoft YaHei", "Source Han Sans CN", sans-serif, "Apple Color Emoji", "Segoe UI Emoji"; margin-top: 14px; margin-bottom: 0px; font-size: 15px; line-height: 1.75; color: rgb(5, 7, 59); text-wrap: wrap;">引用数据类型是Java语言中自定义的数据类型，包括类、接口和数组等。这些类型可以用来封装复杂的数据结构，并且可以定义自己的属性和方法。引用数据类型和基本数据类型不同，它们是通过引用传递的，而不是通过值传递的。这意味着当一个引用类型的变量被传递给一个方法时，方法可以修改该变量引用的对象的状态，但不能直接修改该变量的值。</p><p><br/></p>