var s="_+)(*(*_*(*^^%#!~"; console.log(btoa(s)); // XyspKCooKl8qKCpeXiUjIX4= console.log(atob(btoa(s))); // _+)(*(*_*(*^^%#!~ //console.log(btoa("你好吗？")); // DOMException //console.log(atob("你好吗？")); // DOMException