array_udiff(): Difference between two arrays comparing values through callback function

$new_array = array_udiff ($array1, $array2,....,my_function());

Example with two arrays

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

$first=array('One' =>'First','Two'=>'Second','Three'=>'Third','Fourth');
$second=array('One'=> 'First','2nd','Third');

$result=array_udiff($first,$second,"my_function");
while (list ($key, $val) = each ($result)) {
echo "$key -> $val <br>";
}

Two -> Second 
0 -> Fourth