将url的查询参数解析成字典对象，有两种方法：
1.手动解析
1 function getQueryStringArgs(url){
2 url = url == null ? window.location.href : url;
3 var qs = url.substring(url.lastIndexOf("?") + 1);
4 var args = {};
5 var items = qs.length > 0 ? qs.split('&') : [];
6 var item = null;
7 var name = null;
8 var value = null;
9 for(var i=0; i<items.length; i++){
10 item = items[i].split("=");
11 //用decodeURIComponent()分别解码name 和value（因为查询字符串应该是被编码过的）。
12 name = decodeURIComponent(item[0]);
13 value = decodeURIComponent(item[1]);
14
15 if(name.length){
16 args[name] = value;
17 }
18 }
19
20 return args;
21 }
22 console.log(getQueryStringArgs('https://www.baidu.com/baidu?tn=monline_3_dg&ie=utf-8&wd=12306%E7%81%AB%E8%BD%A6%E7%A5%A8%E7%BD%91%E4%B8%8A%E8%AE%A2%E7%A5%A8%E5%AE%98%E7%BD%91'));
23 // Object {tn: "monline_3_dg", ie: "utf-8", wd: "12306火车票网上订票官网"}
2.使用正则
1 function getQueryObject(url) {
2 url = url == null ? window.location.href : url;
3 var search = url.substring(url.lastIndexOf("?") + 1);
4 var obj = {};
5 var reg = /([^?&=]+)=([^?&=]*)/g;
6 // [^?&=]+表示：除了？、&、=之外的一到多个字符
7 // [^?&=]*表示：除了？、&、=之外的0到多个字符（任意多个）
8 search.replace(reg, function (rs, $1, $2) {
9 var name = decodeURIComponent($1);
10 var val = decodeURIComponent($2);
11 val = String(val);
12 obj[name] = val;
13 return rs;
14 });
15 return obj;
16 }
17 console.log(getQueryObject('https://www.baidu.com/baidu?tn=monline_3_dg&ie=utf-8&wd=12306%E7%81%AB%E8%BD%A6%E7%A5%A8%E7%BD%91%E4%B8%8A%E8%AE%A2%E7%A5%A8%E5%AE%98%E7%BD%91'));
18 // Object {tn: "monline_3_dg", ie: "utf-8", wd: "12306火车票网上订票官网"}