addEventListener和onclick的区别

今天在温习犀牛书的时候，正好看到17章，突然有个疑问，addEventListener和onclick有什么不一样？于是Google查了下，然后用写了个小demo去比较它们，

addEventListener is the way to register an event listener as specified in W3C DOM. Its benefits are as follows:

1. It allows adding more than a single handler for an event. This is particularly useful for DHTML libraries or Mozilla extensions that need to work well even if other libraries/extensions are used.
2. It gives you finer-grained control of the phase when the listener gets activated (capturing vs. bubbling)
3. It works on any DOM element, not just HTML elements.
   下面是中文版的
   
   参考如下：
   这个是英文版本的 https://developer.mozilla.org/en-US/docs/Web/API/EventTarget/addEventListener
   这个是中文版本的https://developer.mozilla.org/zh-CN/docs/Web/API/EventTarget/addEventListener

demo如下，得出结果onclick只出现一次alert：我是click2【很正常第一次click事件会被第二次所覆盖】，但是addEventListener却可以先后运行，不会被覆盖【正如：它允许给一个事件注册多个监听器。在使用DHTML库或者 Mozilla extensions 这样需要保证能够和其他的库或者差距并存的时候非常有用。】

<ul id="color-list">
    <li id="addEvent">red</li>
    <li id="on_click">yellow</li>
</ul>
    <script type="text/javascript">
        (function(){
            var addEvent = document.getElementById("addEvent");
                    addEvent.addEventListener("click",function(){
                        alert("我是addEvent1");
                    },false);
                    addEvent.addEventListener("click",function(){
                        alert("我是addEvent2");
                    },false);

            var addEvent = document.getElementById("on_click"); 

            on_click.onclick = function() {
                alert("我是click1");
            }
            on_click.onclick = function() {
                alert("我是click2");
            }
        })();
    </script>

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