1. Use as a callback function
<?php
echo preg_replace_callback('~-([a-z])~', function ($match) {
return strtoupper($match[1]);
}, 'hello-world');
// 输出 helloWorld
2, as a variable assignment
<?php
$greet = function($name)
{
printf("Hello %s\r\n", $name);
};
$greet('World');
$greet('PHP');
Result:
3. Inherit variables from parent scope
<?php
$message = 'hello';
// 没有 "use"
$example = function () {
var_dump($message);
};
echo $example();
// 继承 $message
$example = function () use ($message) {
var_dump($message);
};
echo $example();
result: