"Uncaught TypeError: a.indexOf is not a function" error when opening new foundation project

Question

I've created a new Foundation 5 project through bash, with foundation new my-project. When I open the index.html file in Chrome an Uncaught TypeError: a.indexOf is not a function error is shown in the console, originating in jquery.min.js:4.

I created the project following the steps on the foundation site, but I can't seem to get rid of this error. Foundation and jQuery look like they are included and linked up correctly in the index.html file, and the linked app.js file is including $(document).foundation();

Does anyone know what is causing this error? and what a solution might be?

Answer 1

This error might be caused by the jQuery event-aliases like .load(), .unload() or .error() that all are deprecated since jQuery 1.8. Lookup for these aliases in your code and replace them with the .on() method instead. For example, replace the following deprecated excerpt:

$(window).load(function(){...});

with the following:

$(window).on('load', function(){ ...});

Answer 2

Please add below jQuery Migrate Plugin

<script src="https://code.jquery.com/jquery-3.3.1.min.js"></script>
<script src="https://code.jquery.com/jquery-migrate-1.4.1.min.js"></script>

Answer 3

This error is often caused by incompatible jQuery versions. I encountered the same error with a foundation 6 repository. My repository was using jQuery 3, but foundation requires an earlier version. I then changed it and it worked.

If you look at the version of jQuery required by the foundation 5 dependencies it states "jquery": "~2.1.0".

Can you confirm that you are loading the correct version of jQuery?

I hope this helps.