PHP: Recursive difference finder of 2 objects

_arrd.php

<?php
    function _arrd($array1, $array2, $label, $depth = 0, $has_diff = false) {
        $array1 = (array)$array1;
        $array2 = (array)$array2;
        if (!$depth) {
            $label .= ': ';
        }
        $diff = array_diff_assoc($array1, $array2);
        if (count($diff)) {
            echo "$label\n";
            foreach ($diff as $diff_key => $diff_value) {
                $left_diff = !is_null($diff_value) ? $diff_value : 'null';
                $right_diff = !is_null($array2[$diff_key]) ? $array2[$diff_key] : 'null';
                echo "\t$diff_key: $left_diff != $right_diff\n";
            }
            $has_diff = true;
        }
        foreach ($array1 as $key => $item) {
            if (is_array($item)) {
                $has_diff = _rd($array1[$key], $array2[$key], $label . "[$key]", $depth + 1, $has_diff);
            }
        }
        if (!$has_diff && !$depth) {
            echo "${label}nasn't diff\n";
        }
        return ($has_diff) ?  true : $has_diff;
    }