<ul id="todo-app">
<li class="item">Walk the dog</li>
<li class="item">Pay bills</li>
<li class="item">Make dinner</li>
<li class="item">Code for one hour</li>
</ul>

'use strict';
document.addEventListener('DOMContentLoaded', function() {

let app = document.getElementById('todo-app');
let items = app.getElementsByClassName('item');

//将事件侦听器绑定到每个列表项
for(let item of items){

item.addEventListener('click', function(){
  alert('you clicked on item: ' + item.innerHTML);
});

}

});

我这这样写的，有什么问题吗