3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = range(1,25); $b = array('21'=>'test'); $t = array_map(function($a){ return associate($a, $b);}, $a); function associate($av, $b) { $r = (isset($b[$av]))?$b[$av]:null; } print_r($t);

preferences:
61.82 ms | 402 KiB | 5 Q