recursive array check PHP

gistfile1.txt

/**
 * check recursive array and spot the diffrence
 * @param $_first_array
 * @param $_second_array
 * @return array
 */
private function recursive_array_check($_first_array, $_second_array) {
	$diff = [];
	foreach($_first_array as $k => $v) {
		if(is_array($v) && isset($_second_array[$k])){
			$_diff = self::recursive_array_check($v, $_second_array[$k]);
			if( !empty($_diff) ) {
				$diff[$k] = $_diff;
			}
		} else if(is_string($v) && !in_array($v, $_second_array)) {
			$diff[$k] = $v . " missing from second array";
		} else if(!is_numeric($k) && !array_key_exists($k, $_second_array)) {
			$diff[$k] = "Missing from second array";
		}
	}
	return $diff;
}