将url地址中的query参数提取出来转成对象

var url = "http://www.baidu.com?username=limei&age=18";

var obj = url.substr(url.indexOf("?")+1).split("&").reduce(function(pre,cur){
        var key = cur.split("=")[0];
        var val = cur.split("=")[1];
        pre[key] = val;
        return pre;
},{})

  console.log(obj)  //{username: "limei", age: "18"}