Use variables inside an anonymous function, which is defined somewhere else

Question

When using anonymous functions in PHP, you can easily use variables from right outside of its scope by using the use() keyword.

In my case the anonymous

Answer 1

FWIW, you can do it if you use a use reference (php.net ex 3.3) and a global, ugly since it uses globals, but just to put it out there:

<?php
$bla = function ( $var1 ) use (&$arg)
        {
            return "var1:$var1, arg:$arg";
        };

class MyClass
{
    private $func;

    public function __construct ( $func )
    {
        $this->func = $func;
    }

    public function test ( $param )
    {
        global $arg;
        $arg=$param;
        $closure =  $this->func;
        return  $closure ( 'anon func' );
    }
}

$c = new MyClass($bla);
echo $c->test ( 'bla bla' ); //var1:anon func, arg:bla bla

Answer 2

The point of the use keyword is to inherit/close over a particular environment state from the parent scope into the Closure when it's defined, e.g.

$foo = 1;

$fn = function() use ($foo) {
    return $foo;
};

$foo = 2;

echo $fn(); // gives 1

If you want $foo to be closed over at a later point, either define the closure later or, if you want $foo to be always the current value (2), pass $foo as a regular parameter.