Online PHP editor | refs for omReZ

<?php $xmls = [6, 3, 2, 5, 4, 1]; echo memory_get_usage() . "\n\n"; usort($xmls, function($a, $b) { static $documents = array(); if (!isset($documents[$a])) { $documents[$a] = true; } if (!isset($documents[$b])) { $documents[$b] = true; } if ($documents[$a] == $documents[$b]) { $result = 0; } else { $result = $documents[$a] < $documents[$b] ? -1 : 1; } echo "a = {$a}, b = {$b}, result = {$result}\n" , memory_get_usage() , "\n" , print_r($documents, true) , "\n"; return $result; }); echo memory_get_usage() . "\n" . print_r($xmls, true) . "\n";