PHP8.1新特性之First-class Callable Syntax

hi，我是温新，一名PHPer

First-Class callables是一种引用闭包和函数的新方法。

php8.1之前版本

<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">$closure</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">Closure</span>::<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">fromCallable</span>(<span style="box-sizing: border-box;color: rgb(152, 195, 121) !important">'array_merge'</span>);</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(232, 191, 106) !important">print_r</span>(<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$closure</span>([<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">1</span>,<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">2</span>], [<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">3</span>,<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">4</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">// Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 )</span></span>

该案使用Closure将array_merge转成一个闭包形式使用。

php8.1版本

<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">$closure</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(232, 191, 106) !important">array_merge</span>(...);</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(232, 191, 106) !important">print_r</span>(<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$closure</span>([<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">1</span>,<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">2</span>], [<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">3</span>,<span style="box-sizing: border-box;color: rgb(209, 154, 102) !important">4</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">// Array ( [0] => 1 [1] => 2 [2] => 3 [3] => 4 )</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">$closure</span> <span style="box-sizing: border-box;color: rgb(86, 182, 194) !important">=</span> <span style="box-sizing: border-box;color: rgb(232, 191, 106) !important">strlen</span>(...);</span><br></br><span style="box-sizing: border-box;color: rgb(171, 178, 191);padding-right: 0.1px"><span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$str</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">'hello'</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(232, 191, 106) !important">print_r</span>(<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$closure</span>(<span style="box-sizing: border-box;color: rgb(224, 108, 117) !important">$str</span>));</span>

保持对技术的热忱

就是对自己最好的驱动