/** * Get all array keys, looking even in arrays contained within the array. * @param array $array * @return array of keys */ function arrayKeysRecursive($array) { $keys = array(); foreach ($array as $key => $item) { $keys[] = $key; if (is_array($item) && !empty($item)) { $keys = array_merge($keys, MyOOS_Utilities::arrayKeysRecursive($item)); } } return $keys; }