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";
} |