where to add js file in html code example

Example 1: import js in html

<script type="text/javascript" src="yourfile.js"></script>

Example 2: how to link your js file to html

<script src="index.js"></script>

Example 3: how to link javascript to html

<script src = "index.js"></script>

Example 4: how to enter javascript in html

<script type="text/javascript">
  alert("This alert box was called with the onload event");
</script>