Compare two integer and count matching numbers

1. Convert the numbers in to strings
2. create a loop from 0-9 to check for the appearance of a number in both strings using strstr() or similar
3. store the number in an array if it appears in both

Edit: Code-centric solution:

$a = 1231534;
$b = 89058430;


    $matches = compare( $a, $b );   
    print count($matches);


    function compare ( $a, $b ) {
        $str_a = (string) $a;
        $str_b = (string) $b;
        $matches = [];
        for($i=0;$i<=9;$i++) {
            if (strstr($str_a, (string)$i) && strstr($str_b,(string)$i)) $matches[] = $i;
        }

        return $matches;
    }