Solution to implement jQuery's $.getJSON using native JavaScript_jquery

Today I am writing a DEMO, which uses jQuery’s $.getJSON method. After writing it, I found that this is the only place in jQuery that is used in the entire DEMO, but it is not cost-effective to introduce a jQuery, so I implemented it myself. A simple version, which can basically meet the needs, is now shared:

Copy the code The code is as follows:

var $ = {
getJSON: function(url, params, callbackFuncName, callback){
var paramsUrl ="",
jsonp = this.getQueryString(url)[callbackFuncName];
for (VAR Key in Params) {
Paramsurl = "&" Key "=" EncodeuricomPonent (Params [Key]);
}
URL = Paramsurl; Data) {
                window[jsonp] = undefined;
if (head) {
head.removeChild(script);
}
callback(data); };

var head = document.getElementsByTagName('head')[0];
var script = document.createElement('script');
script.charset = "UTF-8";
script .src = url;

head.appendChild(script);

return true;
},
getQueryString: function(url) {
var result = {}, queryString = (url && url.indexOf("?")!=-1 && url.split("?")[1]) || location.search.substring(1),
      re = /([^&=] )= ([^&]*)/g, m;
while (m = re.exec(queryString)) {
result[decodeURIComponent(m[1])] = decodeURIComponent(m[2]);
}
}
}
};


Call DEMO as follows:

Copy code

The code is as follows:var url = "http://xxx.xxx.xxx?callback=jsonp123";var params = { a: 1,

b:2

};
$.getJSON(url, params, "callback", function(data){
//todo
});