Is it possible to have 2 different jQuery versions in the same document, and have them to not collide with each other?

For example if I create a bookmarklet and want to base the code on jQuery. This bookmarklet is injected on some page that uses another version of jQuery then my code would overwrite the version used on the page.

Is it possible to avoid that? Or are there some other libraries that provides this functionality Or maybe I should rethink the whole thing.

Thanks for answers and pointers,

bob

Is it possible to have 2 different jQuery versions in the same document, and have them to not collide with each other?

For example if I create a bookmarklet and want to base the code on jQuery. This bookmarklet is injected on some page that uses another version of jQuery then my code would overwrite the version used on the page.

Is it possible to avoid that? Or are there some other libraries that provides this functionality Or maybe I should rethink the whole thing.

Thanks for answers and pointers,

bob

• javascript
• jquery

• 1 You could check if jQuery is already on a page before injecting it again. – Joe Chung Commented Jul 13, 2009 at 1:58
• 3 You should definitely rethink it. You should update older functions to work with the new jQuery, including both is just a ton of bloat and a wish for collisions. – Ian Elliott Commented Jul 13, 2009 at 1:59
• Have you got control over the version of jQuery being added to the page? You don't want your visitors to have to download ANOTHER version of the library if they can help it - it's bad practice and inflates the filesize of the document for your visitors. – Jason Berry Commented Jul 13, 2009 at 4:58
• possible duplicate of Can I use multiple versions of jQuery on the same page? – a'r Commented Sep 23, 2011 at 11:28

3 Answers 3

jQuery comes with a way to avoid collisions. After you load the first version, you can assign it to a different variable.

var $j = jQuery.noConflict();

And then load your second jQuery version. The first one you load can be accessed with $j(...) while the second one can be accessed with $(...).

Alternatively, somebody made a little helper in an attempt to make it easier to switch between different versions.

Here is a way to detect is JQuery is already present: jQuery in widget

Work out the oldest version of JQuery your code will work with.. And refuse to work if the version present is too old. Only a few people will miss out, most sites using JQuery are pretty up to date..

Why not just have different versions of your javascript, for different versions of jquery, so, look at what version is on the page and get the appropriate code that will work on that version of jquery.

This would be safer, as anything else may be very fragile, as it sounds like you don't have control over the version of jquery that will be on the page.