JavaScript/jQuery - "$ is not defined- $function()" error
javascript, jquery
Solution
You must not have made jQuery available to your script.
Add this to the top of your file:
<script type="text/javascript" src="https://code.jquery.com/jquery-1.7.1.min.js"></script>
This issue is related to the jQuery/JavaScript file not added to the PHP/JSP/ASP file properly. This goes out and gets the jQuery code from the source. You could download that and reference it locally on the server which would be faster.
Or either one can directly link it to jQuery or GoogleCDN or MicrosoftCDN.
How do add jQuery to your webpage
Problem
I am trying to run a JavaScript/jQuery function and Firebug gets the error: ``` $ is not defined $(function()". ``` The JavaScript code is placed inside a file called `core.js` and referenced by `index.php`. What causes this error? JavaScript: ``` <script type="text/javascript"> var formObject = { run : function(obj) { if (obj.val() === '') { obj.nextAll('.update').html('<option value="">----</option>').attr('disabled', true); } else { var id = obj.attr('id'); var v = obj.val(); jQuery.getJSON('/mod/update.php', { id : id, value : v }, function(data) { if (!data.error) { obj.next('.update').html(data.list).removeAttr('disabled'); } else { obj.nextAll('.update').html('<option value="">----</option>').attr('disabled', true); } }); } } }; $(function() { $('.update').live('change', function() { formObject.run($(this)); }); }); </script> ``` PHP/HTML ``` <html> <select name="main" id="category" class="update"> <option value="">Select one</option> <? if (!empty($list)) { ?> <? foreach($list as $row) { ?> <option value="<?php echo $row['id']; ?>"> <? echo $row['name']; ?> </option> <? } ?> <? } ?> </select> </html> ```