Ajax json

keyword : XML HttpRequest

example : 

function ajax(method,url,data,e) {

let xmlhttp = new XMLHttpRequest();

xmlhttp.open(method, url, true);

xmlhttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');

xmlhttp.setRequestHeader('X-Reqeusted-With', 'XMLHttpRequest');

xmlhttp.onreadystatechange = function() {

if(xmlhttp.readyState == XMLHttpRequest.DONE && xmlhttp.status == 200 ) {

data = xmlhttp.responseText;

let item = JSON.parse(data);

e(item);

}

}

xmlhttp.send(data);

}