Migrating to jquery 1.4

I 开发者_C百科would like to upgrade a site from 1.3.2 to 1.4 as I see there are some good performance improvements.

1. Can I simply drop this in or should I be concerned about my plugins working?

2. Is it backward compatible?

3. What should I be worrying about?

Check this page: http://jquery14.com/day-01/jquery-14 (cached version from web.archive.org)

On the bottom there's a list of breaking changes. It will give you an idea if there are issues for you.

There's also a plugin which makes jQuery 1.4 compatible with 1.3.

you should be fine but there are a list of potential issues here:

http://jquery14.com/day-01#backwards

Best bet is to try it and see. jQuery14.com has a backward compatibility list, as well as a 1.3-compat plugin you can use to soften the blow.

I've done the same thing the other day and had no issues. One interestng thing is that the site claims that 1.4 no longer defaults $() to $(document).ready - I do however have such code and it is working fine...