问题
Does addEventListener overwrites previously defined actions for a particular event?For example,
<input type="text" name="ele" id="eleID" onfocus="doSomeThing();"/>
Now if I add another action for the same event,will both both function get executed?
eleID.addEventListener('focus',doSomethingElse,false);
If doSomethingElse() overwrites doSomeThing(), is there any other way to do it?
回答1:
No.
From MDC:
addEventListener is the way to register an event listener as specified in W3C DOM. Its benefits are as follows:
- It allows adding more than a single handler for an event.
See example.
回答2:
No, it does not "overwrite" other handlers; that's why it's called "addEventListener". All the handlers are invoked when an event happens.
Now, I will say that mixing the old-style "DOM 0" event handler attachment mechanism (the "onevent" attributes) with event handlers added with "addEventListener()" is not a very good practice.
来源：https://stackoverflow.com/questions/6227667/addeventlistener-overwrites-other-event-actions