开发中的编码和解码（js的问题）

var url = "http://www.baidu.com?name=张三&age=23";
console.log(escape(url));
//   http%3A//www.baidu.com%3Fname%3D%u5F20%u4E09%26age%3D23
 
var escapeUrl = "http%3A//www.baidu.com%3Fname%3D%u5F20%u4E09%26age%3D23";
console.log(unescape(escapeUrl));
// http://www.baidu.com?name=张三&age=23

var url = "http://www.baidu.com?name=张三&age=23";
console.log(encodeURI(url));
// http://www.baidu.com?name=%E5%BC%A0%E4%B8%89&age=23
 
var escapeUrl = "http://www.baidu.com?name=%E5%BC%A0%E4%B8%89&age=23";
console.log(decodeURI(escapeUrl));
// http://www.baidu.com?name=张三&age=23

var url = "http://www.baidu.com?name=张三&age=23";
console.log(encodeURIComponent(url));
// http%3A%2F%2Fwww.baidu.com%3Fname%3D%E5%BC%A0%E4%B8%89%26age%3D23
 
var escapeUrl = "http%3A%2F%2Fwww.baidu.com%3Fname%3D%E5%BC%A0%E4%B8%89%26age%3D23";
console.log(decodeURIComponent(escapeUrl));
// http://www.baidu.com?name=张三&age=23