Callback function using variables calculated outside of it

Question

Basically I\'d like to do something like this:

$arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
$avg = array_sum($arr) / count($arr);
$callback = function($val){ retu         


        

Answer 1

You can use the use keyword to inherit variables from the parent scope. In your example, you could do the following:

$callback = function($val) use ($avg) { return $val < $avg; };

For more information, see the manual page on anonymous functions.

Answer 2

use global variables i.e $GLOBAL['avg']

$arr = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
$GLOBALS['avg'] = array_sum($arr) / count($arr);
$callback = function($val){ return $val < $GLOBALS['avg'] };

$return array_filter($arr, $callback);