TypeError: 'undefined' is not a function (

Question

1. I'm using a WordPress site.
2. I'm including this script in the header.

When the script loads, I get this error:

TypeError: 'undefined' is not a function (evaluating '$(document)')

I have no idea what is causing it or what it even means.

In firebug, I get this:

$ is not a function

Answer 1

Also check for including jQuery, followed by some components/other libraries (like jQuery UI) and then accidentially including jQuery again - this will redefine jQuery and drop the component helpers (like .datepicker) off the instance.

Answer 2

I had this problem only on Chrome.

I tried adding

var $ =jQuery.noConflict();

just before calling

$(document).ready(function () {

It worked.

Thanks a lot

Answer 3

Use this:

var $ =jQuery.noConflict();

Answer 4

 ;(function($){
        // your code
    })(jQuery);

Place your js code inside the closure above , it should solve the problem.

Answer 5

Two things:

1. Be sure that you have jQuery library added, before your $(document).
2. Then just change all "$" with: jQuery , as the previous comments.

Answer 6

wrap all the script between this...

<script>
    $.noConflict();
    jQuery( document ).ready(function( $ ) {
      // Code that uses jQuery's $ can follow here.
    });
</script>

Many JavaScript libraries use $ as a function or variable name, just as jQuery does. In jQuery's case, $ is just an alias for jQuery, so all functionality is available without using $. If you need to use another JavaScript library alongside jQuery, return control of $ back to the other library with a call to $.noConflict(). Old references of $ are saved during jQuery initialization; noConflict() simply restores them.