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Anonymous functions
(Anonymous functions) in PHP
are also called closure functions
(closures), allows specifying a function without a name. The most commonly used one is the parameter value of callback function
.
1. Reference local variables in anonymous functions (use the use keyword in PHP here).
<?php function F1(){ $ok="HelloWorld"; $a=function() use($ok) { echo "$ok"; }; $a(); } F1(); ?>
2. Place the anonymous function in a normal function, or return the anonymous function.
<?php function F1(){ $a=function() { echo "HelloWorld"; }; $a(); } F1(); ?>
3. Return in an ordinary function.
<?php function F1(){ $a=function() { echo "HelloWorld"; }; return $a; } $abc=F1(); $abc(); ?>
4. Return the anonymous function and pass parameters to the anonymous function.
<?php function F1(){ $a=function($name,$do) { echo $name." ".$do." HelloWorld"; }; return $a; } $abc=F1(); $abc('张三','say'); ?>
5. Pass anonymous functions as parameters.
<?php function F1($UnkownFun){ $UnkownFun("张三"); } F1(function ($username){ echo $username; }); ?>
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