PHP8.0 match表达式

match 语法：

<span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$returnValue</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">match</span> (<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">exp</span>) {</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">   <span style="box-sizing: border-box;color: rgb(98, 151, 85) !important">// 单条件表达式</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">single_conditional_expression</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">return_expression</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(98, 151, 85) !important">// 多条件表达式</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">conditional_expression1</span>, <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">conditional_expression2</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">return_expression</span>,  </span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">};</span>

match 表达式基于值的一致性进行分支计算。 match表达式和 switch 语句类似， 都有一个表达式主体，可以和多个可选项进行比较。 与 switch 不同点是，它会像三元表达式一样求值。 与 switch 另一个不同点，它的比较是严格比较（ ===）而不是松散比较（==）

macth注意点:

• match使用 ===进行严格比较；
• match表达式必须以;结尾；

match表达式与switch的区别：

• match 比较分支值，使用了严格比较 (===)， 而 switch 语句使用了松散比较。
• match 表达式会返回一个值。
• match 的分支不会像 switch 语句一样， 落空时执行下个 case。
• match 表达式必须彻底列举所有情况。

单条条件基础用法：

<span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">10</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$result</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">match</span> (<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>) {</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">5</span>   <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>  <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'我返回了 '</span> . <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">10</span>  <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>  <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'我返回了 '</span> . <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">15</span>  <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>  <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'我返回了 '</span> . <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">};</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(98, 151, 85) !important">// 10</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">echo</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$result</span>;</span>

多条件用法：

<span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(86, 182, 194) !important"><?</span><span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">php</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">  </span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$language</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'php'</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$result</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">match</span> (<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$language</span>) {</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'php'</span>   <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>  <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'PHP是世界上最好的语言'</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'vue'</span>,<span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'react'</span>   <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>  <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'都是js框架'</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">default</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>  <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'啥也不是'</span>,</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">};</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(98, 151, 85) !important">// PHP是世界上最好语言</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">echo</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$result</span>;</span>

当$language为 vue或react时，将输出都是js框架；

当$language为 其他值时，输出 default所默认的结果 啥也不是。

表达式用法

<span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(86, 182, 194) !important"><?</span><span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">php</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">  </span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">class</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">A</span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">{</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">public</span> <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">function</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">getA</span>()</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    {</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">        <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">return</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">10</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    }</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">}</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$a</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">new</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">A</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">function</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">num</span> (<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>) {</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">return</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">*</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">2</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">}</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">function</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">getWebName</span>()</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">{</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">return</span> <span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'自如初'</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">}</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">10</span>;</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$result</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">match</span> (<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>) {</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$a</span><span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">-></span><span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">getA</span>() <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>   <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">getWebName</span>(),</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">    <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">5</span>          <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=></span>   <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">num</span>(<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$num</span>),</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px">};</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box"></span></span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(198, 120, 221) !important">echo</span> <span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$result</span>;</span>

我是温新

每天进步一点点，就一点点

我很喜欢的一句话，分享一下，出自《SQL进阶》

这个世界没有一天是无聊的，只不过是你懒惰已久的感官无法发现眼前事物的乐趣。