TypeError: $ is not a function when calling jQuery

Question

I have a simple jQuery script in a WordPress plugin that is using a jQuery wrapper like this:

$(document).ready(function(){

    // jQuery code is in here

});

I am calling this script from within the WordPress Dashboard and am loading it AFTER the jQuery framework has loaded.

When I check the page in Firebug I constantly keep receiving the error message:

TypeError: $ is not a function

$(document).ready(function(){

Should I maybe wrap the script in this function:

(function($){

    // jQuery code is in here

})(jQuery);

I have had this error quite a few times and am not sure how to handle it.

Any help would be greatly appreciated.

Answer 1

Double check your jQuery references. It is possible that you are either referencing it more than once or you are calling your function too early (before jQuery is defined). You can try as mentioned in my comments and put any jQuery reference at the top of your file (in the head) and see if that helps.

If you use the encapsulation of jQuery it shouldn't help in this case. Please try it because I think it is prettier and more obvious, but if jQuery is not defined you will get the same errors.

In the end... jQuery is not currently defined.

Answer 2

You have to pass $ in function()

<script>
jQuery(document).ready(function($){

// jQuery code is in here

});
</script>

Answer 3

You can avoid confliction like this

var jq=jQuery.noConflict();
jq(document).ready(function(){  
  alert("Hi this will not conflict now");
  jq('selector').show();
});