nested Array search by value or key

<?php
 
//PHP 5.3
 
function searchNestedArray(array $array, $search, $mode = 'value') {
 
    foreach (new RecursiveIteratorIterator(new RecursiveArrayIterator($array)) as $key => $value) {
        if ($search === ${${"mode"}})
            return true;
    }
    return false;
}
 
$data = array(
    array('abc', 'ddd'),
    'ccc',
    'bbb',
    array('aaa', array('yyy', 'mp' => 555))
);
 
var_dump(searchNestedArray($data, 555));