SOURCE

// 仅支持浏览器端
function encode (str) {
	return btoa(encodeURIComponent(str));
}

function decode (str) {
	return decodeURIComponent(atob(str));
}

var res = encode("Hello+World")
console.log(res)
var ress = decode("SGVsbG8lMkJXb3JsZA==")
console.log(ress)