CI_Session::tempdata PHP Method

    public function tempdata($key = NULL)
    {
        if (isset($key)) {
            return isset($_SESSION['__ci_vars'], $_SESSION['__ci_vars'][$key], $_SESSION[$key]) && is_int($_SESSION['__ci_vars'][$key]) ? $_SESSION[$key] : NULL;
        }
        $tempdata = array();
        if (!empty($_SESSION['__ci_vars'])) {
            foreach ($_SESSION['__ci_vars'] as $key => &$value) {
                is_int($value) && ($tempdata[$key] = $_SESSION[$key]);
            }
        }
        return $tempdata;
    }