note 41593 added to function.shuffle

This code is very appealing in its simplicity and speed, but it's not a random shuffle: <?php function randomcmp($a, $b) { return mt_rand(-1, 1); } function swapshuffle(&$array) { srand((double) microtime() * 10000000); uksort($array, "randomcmp"); } ?> This is because uksort calls the C function zend_qsort and this quicksorts the array using the provided comparision function. The pairs of indices selected are biased by the nature of the quicksort algorithm. One effect is that an element in the middle of the array is heavily biased toward being "shuffled" to the middle. Elements on the edges are biased towards the edges; they're likely to switch edges, but unlikely to end up in the middle. ---- Manual Page -- http://www.php.net/manual/en/function.shuffle.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+41593 Delete -- http://master.php.net/manage/user-notes.php?action=delete+41593&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+41593&report=yes Search -- http://master.php.net/manage/user-notes.php