That error can only be caused by one of three things:
- Your JavaScript file is not being properly loaded into your page
- You have a botched version of jQuery. This could happen because someone edited the core file, or a plugin may have overwritten the $ variable.
- You have JavaScript running before the page is fully loaded, and as such, before jQuery is fully loaded.
- shouldn’t have attributes async or defer.
Jquery live CDN Url
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
Simple Jquery Example
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
$(document).ready(function(){
$("p").click(function(){
$(this).hide();
});
});
</script>
</head>
<body>
<p>If you click on me, I will disappear.</p>
<p>Click me away!</p>
</body>
</html>