Simple example of PHP closure definition and usage

This article mainly introduces the definition and use of PHP closures. It has certain reference value. Now I share it with everyone. Friends in need can also refer to it.

The examples in this article describe the definition and use of PHP closures. use. Share it with everyone for your reference, the details are as follows:

<?php
function getClosure($i)
{
  $i = $i.&#39;-&#39;.date(&#39;H:i:s&#39;);
  return function ($param) use ($i) {
    echo "--- param: $param ---\n";
    echo "--- i: $i ---\n";
  };
}
$c = getClosure(123);
$i = 456;
$c(&#39;test&#39;);
sleep(3);
$c2 = getClosure(123);
$c2(&#39;test&#39;);
$c(&#39;test&#39;);
/*
output:
--- param: test ---
--- i: 123-21:36:52 ---
--- param: test ---
--- i: 123-21:36:55 ---
--- param: test ---
--- i: 123-21:36:52 ---
*/

Another example

$message = 'hello';
$example = function() use ($message){
 var_dump($message);
};
echo $example();
//输出hello
$message = 'world';
//输出hello 因为继承变量的值的时候是函数定义的时候而不是 函数被调用的时候
echo $example();
//重置为hello
$message = 'hello';
//此处传引用
$example = function() use(&$message){
 var_dump($message);
};
echo $example();
//输出hello
$message = 'world';
echo $example();
//此处输出world
//闭包函数也用于正常的传值
$message = 'hello';
$example = function ($data) use ($message){
 return "{$data},{$message}";
};
echo $example('world');
//此处输出world,hello

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Instructions for the practical application of php closure features

Detailed explanation of php closure function code examples

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