Wordpress & jQuery: “$ is not a function”

Posted by chad on August 18th, 2009 | 16 comments

If you are trying to add your own jQuery code to Wordpress, and have had the error “$ is not a function” show up on Firebug, here is the fix:

Convert all dollar signs ($) to ‘jQuery’

The dollar sign is reserved in Wordpress for the Prototype library, which is why it errors out. For example, instead of:

$().ready(function() {
   $("#select_me").show();
});

Change it to:

jQuery().ready(function() {
   jQuery("#select_me").show();
});

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On September 09, 2009 Fabian says:

Yeah, you saved my day!
On November 05, 2009 Blair says:

Sweetness! Somethings are too easy…for some people.
On December 09, 2009 Matt Cassarino says:

Nice, this helps a lot! Thanks.
On December 14, 2009 Natasha says:

Thank you so much for posting this, because I was at my wits end!
On December 29, 2009 Matt says:

Thanks; great reminder!
On January 08, 2010 Andy says:

Thanks, God Bless…
On January 11, 2010 Mv_Embed in use for html5 videos | AHunt.org says:

[...] my wordpress theme’s (!) scripts. This turned out to be a jQuery problem, explained in a post here. Strangely enough editing the mv_embed script was not enough to fix the page, and the theme’s [...]
On January 19, 2010 Nick says:

Thank You So Much for this!!
On January 23, 2010 Andrey says:

10x a lot!!!
On January 28, 2010 worldwisewebs says:

wow so simple. Thanks
On February 07, 2010 Rey Bango says:

You should definitely consider using jQuery’s noConflict() method as another alternative.

http://docs.jquery.com/Using_jQuery_with_Other_Libraries

Rey – jQuery Team
On February 10, 2010 Mark says:

Whew… I was bashing my head on the keyboard already. Thanks!
On February 11, 2010 Brian says:

Thanks for this. Guess what? It works for Plone too!
On February 12, 2010 Justin says:

Thank you, most helpful!
On February 24, 2010 droope says:

Wow, thanks. That’s why,.
On February 24, 2010 GChatzop says:

Ty so much

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