usort

Description

void usort(array array, function cmp_function);

This function will sort an array 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().