CI_Form_validation::_reduce_array PHP 메소드

    protected function _reduce_array($array, $keys, $i = 0)
    {
        if (is_array($array) && isset($keys[$i])) {
            return isset($array[$keys[$i]]) ? $this->_reduce_array($array[$keys[$i]], $keys, $i + 1) : NULL;
        }
        // NULL must be returned for empty fields
        return $array === '' ? NULL : $array;
    }