3v4l.org

run code in 300+ PHP versions simultaneously
<?php $a = [1,2,3,4,5,6,1,2,3,4,5,6]; $f = function($a,$b) { return $a < $b ? 1 : ($a > $b ? -1 : 0); }; uasort($a, $f); print_r($a); var_dump($x);
Output for 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
Array ( [5] => 6 [11] => 6 [4] => 5 [10] => 5 [3] => 4 [9] => 4 [2] => 3 [8] => 3 [1] => 2 [7] => 2 [0] => 1 [6] => 1 ) Warning: Undefined variable $x in /in/6pcKu on line 14 NULL
Output for 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.31, 7.4.0 - 7.4.33
Array ( [5] => 6 [11] => 6 [4] => 5 [10] => 5 [3] => 4 [9] => 4 [2] => 3 [8] => 3 [1] => 2 [7] => 2 [0] => 1 [6] => 1 ) Notice: Undefined variable: x in /in/6pcKu on line 14 NULL
Output for 7.3.32 - 7.3.33
Array ( [5] => 6 [11] => 6 [4] => 5 [10] => 5 [3] => 4 [9] => 4 [2] => 3 [8] => 3 [1] => 2 [7] => 2 [0] => 1 [6] => 1 ) NULL
Output for 5.5.24 - 5.5.35, 5.6.8 - 5.6.28
Array ( [11] => 6 [5] => 6 [10] => 5 [4] => 5 [9] => 4 [3] => 4 [8] => 3 [2] => 3 [1] => 2 [7] => 2 [6] => 1 [0] => 1 ) Notice: Undefined variable: x in /in/6pcKu on line 14 NULL
preferences:
147.36 ms | 402 KiB | 213 Q