bind events on body or document?

问题

sometimes the users bind the events on $('body') and sometimes on $(document)

$(document).on('click', someAction);

$('body').on('click', someAction);

Is there some reason to prefer one to another?

回答1:

For me, there is mainly one reason to bind the events on $(document) and not to $('body'):

no need to wait domReady (document is available before everything else)

回答2:

Short answer most likely is, no, not really.

The reason someone is doing it should always be that he requires to catch an event globally in his markup. Since the <body> tag should follow as direct sibling to <html>, all events bubbling phase will end there.

<html>
    <body>
         <div>
         </div>

Every click event on <div> would bubble up to <body> as well as <html> (if not stopped manually). So for that usecase it should not make any difference.

回答3:

There is some difference in speed, not much else. Someone has already done the work though so I'll just point you the link.

http://jsperf.com/jquery-body-vs-document-body-selector

However, in direct relation to your code there, there is one major difference. $(document).on('click', someAction); will affect anywhere on the document viewing area, whereas $('body').on('click', someAction); Might not affect as much area as body can have an independent height and width.

来源：https://stackoverflow.com/questions/13687269/bind-events-on-body-or-document

标签

javascript

jquery

javascript-events