双11，自动领取优惠券 js 代码

http://www.zhihu.com/question/36426051/answer/67690322

本来我不熟悉 js，正好研究一下

 (function(window, document) {
     var interval = 800;
     var closeDelay = 200;
     var index = 0;
     var couponLinks;
     var getCoupon = function() {
         if (index >= couponLinks.length) {
             console.log("领取完毕");
             return;
         }
         var coponLink = couponLinks[index];
         coponLink.click();
         index++;
         console.log("领取 第" + index + " 张");
         setTimeout(getCoupon, interval);
         setTimeout(function() {
             var close = document.querySelector('.mui-dialog-close');
             if (close != null) close.click();
         }, closeDelay);
     }

     var _scrollTop = 0;
     var _scrollStep = document.documentElement.clientHeight;
     var _maxScrollTop = document.body.clientHeight - _scrollStep;

     var autoScrollDown = setInterval(function() {
         _scrollTop += _scrollStep;
         if (_scrollTop <= _maxScrollTop) {
             document.body.scrollTop = _scrollTop;
             return;
         }
         clearInterval(autoScrollDown);

         couponLinks = document.querySelectorAll('.mui-act-item-yhqbtn');
         console.log("总共：" + couponLinks.length + "条张优惠券待领取…");
         getCoupon();
     }, 500);
 }) (window, document);

搜一下关键的几个函数和变量，就很容易理解了。

document.querySelector
document.querySelectorAll
document.documentElement.clientHeight
document.body.clientHeight
document.body.scrollTop
setInterval
setTimeout

搞明白了这几含义，写个自动领券的代码还不是分分钟～