When was function use closures implemented in PHP? [duplicate]

问题

This question already has answers here:

In PHP, what is a closure and why does it use the “use” identifier? (6 answers)

Closed 5 years ago.

I couldn't find the section in the PHP manual that explains use

I have the code

$num = 0;
array_walk_recursive($_REQUEST, function($mValue) use (&$num){
           $num++;
        });

and my Eclipse complains:

Parser error "'{' expected in compound-statement.

So I guess this was implemented in some PHP version.

回答1:

Anonymous functions/closures and the use language construct were implemented in version 5.3.0

@see changelog: http://php.net/manual/en/functions.anonymous.php

来源：https://stackoverflow.com/questions/20411631/when-was-function-use-closures-implemented-in-php