<?php $sortKey = 1; return $v[$sortKey]; }, $arr1), $arr1);
Standard input is empty
Array ( [0] => Array ( [0] => 12 [1] => 8 [2] => 5 [3] => 34 ) [1] => Array ( [0] => 53 [1] => 16 [2] => 24 [3] => 19 ) [2] => Array ( [0] => 23 [1] => 76 [2] => 98 [3] => 13 ) [3] => Array ( [0] => 54 [1] => 87 [2] => 32 [3] => 10 ) )