js实现为a标签添加事件的方法(使用闭包循环)

<ul>
    <li><a href="javascript:;" class="ml-praise">数量：<span class="ding-num">100</span></a></li>
    <li><a href="javascript:;" class="ml-praise">数量：<span class="ding-num">200</span></a></li>
    <li><a href="javascript:;" class="ml-praise">数量：<span class="ding-num">300</span></a></li>
    <li><a href="javascript:;" class="ml-praise">数量：<span class="ding-num">400</span></a></li>
</ul>

function addPraiseNum() {
  var praiseObjs = document.getElementsByClassName('ml-praise');
  for (var i = 0; i < praiseObjs.length; i++) {
 var praiseObj = praiseObjs[i];
 praiseObj.onclick = (function (dingObj) {
   return function () {
 dingObj.innerHTML = parseInt(dingObj.innerHTML) + 1;
   };
 })(praiseObj.getElementsByClassName(&#39;ding-num&#39;)[0]);
  }
}