手写AJAX

背代码，完整版

var request = new XMLHttpRequest()

request.open('GET', '/a/b/c?name=ff', true);

request.onreadystatechange = function () {

  if(request.readyState === 4 && request.status === 200) {

    console.log(request.responseText);

  }};

request.send();

背代码，简化版

var request = new XMLHttpRequest()

request.open('GET', '/a/b/c?name=ff', true)

request.onload = ()=> console.log(request.responseText)

request.send()