Uncaught Reference Error: jQuery is not defined

You are getting this error in your ASP.NET Core application. Your Layout page has the proper reference;

    <script src="~/lib/jquery/dist/jquery.js"></script>

When you try to navigate to your content page where you want to use jQuery;

$(function () {
      alert("Test");

You see above error. Dammit. What’s wrong. jQuery library is referenced in Layout page and suppose to work in content page.

Chances are that you have not defined script section in your Layout page.

@section Scripts {
  <script>
    $(function () {
      alert("Test"); 
    });
  </script>
}

This will solve the problem and pain will go away.