uksort

Description

This function will sort the keys of 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.

function cmp ($a, $b) {
    if ($a == $b) return 0;
    return ($a > $b) ? -1 : 1;
}

$a = array (4 => "four", 3 => "three", 20 => "twenty", 10 => "ten");

uksort ($a, "cmp");

while (list ($key, $value) = each ($a)) {
    echo "$key: $value\n";
}

This example would display:

20: twenty 10: ten 4: four 3: three

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