原生js ajax

  /* 封装ajax函数
        * @param {string}opt.method http连接的方式，包括POST和GET两种方式
        * @param {string}opt.url 发送请求的url
        * @param {boolean}opt.async 是否为异步请求，true为异步的，false为同步的
        * @param {object}opt.data 发送的参数，格式为对象类型
        * @param {function}opt.success ajax发送并接收成功调用的回调函数
        */
       function ajax(opt) {
           opt = opt || {};
           opt.method = opt.method.toUpperCase() || 'POST';
           opt.url = opt.url || '';
           opt.async = opt.async || true;
           opt.data = opt.data || null;
           opt.success = opt.success || function () {};
           var xmlHttp = null;
           if (XMLHttpRequest) {
               xmlHttp = new XMLHttpRequest();
           }
           else {
               xmlHttp = new ActiveXObject('Microsoft.XMLHTTP');
           }var params = [];
           for (var key in opt.data){
               params.push(key + '=' + opt.data[key]);
           }
           var postData = params.join('&');
           if (opt.method.toUpperCase() === 'POST') {
               xmlHttp.open(opt.method, opt.url, opt.async);
               xmlHttp.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded;charset=utf-8');
               xmlHttp.send(postData);
           }
           else if (opt.method.toUpperCase() === 'GET') {
               xmlHttp.open(opt.method, opt.url + '?' + postData, opt.async);
               xmlHttp.send(null);
           }
           xmlHttp.onreadystatechange = function () {
               if (xmlHttp.readyState == 4 && xmlHttp.status == 200) {
                   opt.success(xmlHttp.responseText);
               }
           };
       }


       ajax({
           method: 'POST',
           url: 'test.php',
           data: {'mobile':value},
           success: function (response) {
               console.log(response);
           }
       });