js converts address parameters into json objects

1. The so-called url parameter, that is, the content after the "?" in the address bar

2. Example + Analysis

(1) Get the content after "?" in the address bar

// directly acquired (content after acquisition?)
var search = window.location.search;  // 例如："?userName=cyq&age=24&sex=f"
// dead address
var href = "http://www.cyqzy.com?userName=cyq&age=24&sex=f";
var ksbz = href.indexOf("?");
// Three ways to intercept the string and return the result: userName=cyq&age=24&sex=f
var hrefStr = href.substr(ksbz+1);  // 参数(start,length)
var hrefStr2 = href.substring(ksbz+1); // parameter (start,end), the return result does not include end
var hrefStr3 = href.slice(ksbz+1); // parameter (start,end), the return result does not include end

(2) Method 1 (returns a json object)

var splitStr = hrefStr.split("&");  // 返回结果：["userName=cyq", "age=24", "sex=f"]
var urlObj = {} // equivalent to var urlObj = new Object()
for(var i = 0; i < splitStr.length; i++){
  urlObj[splitStr[i].split("=")[0]] = splitStr[i].split("=")[1];
}
console.log(urlObj) // 返回结果：Object {userName: "cyq", age: "24", sex: "f"}

(3) Method 2 (get parameter value)

var name = "age"; // name refers to the attribute name to be taken, such as username or age or sex
var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
var res = hrefStr.match(reg);
if (res != null){
  console.log(res);//["&age=24&", "&", "24", "&", index: 12, input: "userName=cyq&age=24&sex=f"]
  console.log(res[2]); // 24
}