3v4l.org

run code in 200+ php & hhvm versions
Bugs & Features
<?php $array = [1,2,3,4,5,6,7,8,9]; $expect = [1,4,7,2,5,8,3,6,9]; $a = usort($array, function ($a, $b){ $arow = 3 - $a%3; $brow = 3 - $b%3; $acol = 3 - intval($a/3); $bcol = 3 - intval($b/3); return $acol == $bcol?($arow - $brow):$acol - $bcol; }); print_r($array);
based on tPpnK
Output for 5.4.0 - 7.3.0rc4
Array ( [0] => 9 [1] => 8 [2] => 7 [3] => 6 [4] => 5 [5] => 4 [6] => 3 [7] => 2 [8] => 1 )
Output for 4.4.2 - 4.4.9, 5.1.0 - 5.3.29
Parse error: syntax error, unexpected '[' in /in/BDQId on line 3
Process exited with code 255.
Output for 4.3.0 - 4.3.1, 4.3.5 - 4.4.1, 5.0.0 - 5.0.5
Parse error: parse error, unexpected '[' in /in/BDQId on line 3
Process exited with code 255.
Output for 4.3.2 - 4.3.4
Parse error: parse error in /in/BDQId on line 3
Process exited with code 255.