usort

Description

This function will sort an array by its values using a user-supplied comparison function. If the array you wish to sort needs to be sorted by some non-trivial criteria, you should use this function.

Example 1. usort() example function cmp($a,$b) { if ($a == $b) return 0; return ($a > $b) ? -1 : 1; } $a = array(3,2,5,6,1); usort($a, cmp); while(list($key,$value) = each($a)) { echo "$key: $value\n"; }

This example would display: 0: 6 1: 5 2: 3 3: 2 4: 1 Obviously in this trivial case the rsort() function would be more appropriate.

See also arsort(), asort(), ksort(), rsort() and sort().