referenceerror is not defined nodejs code example

Example 1: ReferenceError: fs is not defined node js

// Define the `fs` at the beginning of the script
const fs = require('fs');

Example 2: Uncaught ReferenceError: $ is not defined

You should put the references to the jquery scripts first.
<script src="jquery-3.5.1.js"></script>
<script type="text/javascript" src="script.js"></script>