本文实例讲述了JS实现的base64加密解密操作。分享给大家供大家参考，具体如下：
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>js base64加密解密</title>
</head>
<body>
<script>
// 创建Base64对象
var Base64 = {
_keyStr: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
encode: function(e) {
var t = "";
var n, r, i, s, o, u, a;
var f = 0;
e = Base64._utf8_encode(e);
while (f < e.length) {
n = e.charCodeAt(f++);
r = e.charCodeAt(f++);
i = e.charCodeAt(f++);
s = n 2;
o = (n & 3) << 4 | r 4;
u = (r & 15) << 2 | i 6;
a = i & 63;
if (isNaN(r)) {
u = a = 64
} else if (isNaN(i)) {
a = 64
}
t = t + this._keyStr.charAt(s) + this._keyStr.charAt(o) + this._keyStr.charAt(u) + this._keyStr.charAt(a)
}
return t
},
decode: function(e) {
var t = "";
var n, r, i;
var s, o, u, a;
var f = 0;
e=e.replace(/[^A-Za-z0-9+/=]/g,"");
while (f < e.length) {
s = this._keyStr.indexOf(e.charAt(f++));
o = this._keyStr.indexOf(e.charAt(f++));
u = this._keyStr.indexOf(e.charAt(f++));
a = this._keyStr.indexOf(e.charAt(f++));
n = s << 2 | o 4;
r = (o & 15) << 4 | u 2;
i = (u & 3) << 6 | a;
t = t + String.fromCharCode(n);
if (u != 64) {
t = t + String.fromCharCode(r)
}
if (a != 64) {
t = t + String.fromCharCode(i)
}
}
t = Base64._utf8_decode(t);
return t
},
_utf8_encode: function(e) {
e = e.replace(/rn/g, "n");
var t = "";
for (var n = 0; n < e.length; n++) {
var r = e.charCodeAt(n);
if (r < 128) {
t += String.fromCharCode(r)
} else if (r > 127 && r < 2048) {
t += String.fromCharCode(r 6 | 192);
t += String.fromCharCode(r & 63 | 128)
} else {
t += String.fromCharCode(r 12 | 224);
t += String.fromCharCode(r 6 & 63 | 128);
t += String.fromCharCode(r & 63 | 128)
}
}
return t
},
_utf8_decode: function(e) {
var t = "";
var n = 0;
var r = c1 = c2 = 0;
while (n < e.length) {
r = e.charCodeAt(n);
if (r < 128) {
t += String.fromCharCode(r);
n++
} else if (r > 191 && r < 224) {
c2 = e.charCodeAt(n + 1);
t += String.fromCharCode((r & 31) << 6 | c2 & 63);
n += 2
} else {
c2 = e.charCodeAt(n + 1);
c3 = e.charCodeAt(n + 2);
t += String.fromCharCode((r & 15) << 12 | (c2 & 63) << 6 | c3 & 63);
n += 3
}
}
return t
}
}
// 定义字符串
var string = 'Hello World!';
// 加密
var encodedString = Base64.encode(string);
console.log(encodedString); // 输出: "SGVsbG8gV29ybGQh"
// 解密
var decodedString = Base64.decode(encodedString);
console.log(decodedString); // 输出: "Hello World!"
</script>
</body>
</html>
运行结果：
PS：这里再推荐几款加密解密相关在线工具供大家参考使用：
在线编码转换工具(utf-8/utf-32/Punycode/Base64)：
http://tools.jb51.net/transcoding/decode_encode_tool
BASE64编码解码工具：
http://tools.jb51.net/transcoding/base64
图片转换为Base64编码在线工具：
http://tools.jb51.net/transcoding/img2base64
更多关于JavaScript相关内容可查看本站专题：《JavaScript加密解密技巧汇总》、《JavaScript查找算法技巧总结》、《JavaScript错误与调试技巧总结》、《JavaScript数据结构与算法技巧总结》、《JavaScript遍历算法与技巧总结》及《JavaScript数学运算用法总结》
希望本文所述对大家JavaScript程序设计有所帮助。