use js in html code example
Example 1: include script in html
<script type="text/javascript" src="/path/to/script.js"></script>
Example 2: how to use javascript in html
<!-- include an external javascript document -->
<script src="myJavaScript.js" charset="utf-8"></script>
<!-- JavaScript inside html element -->
<script>
console.log("This is JavaScript");
</script>
Example 3: how to enter javascript in html
<script type="text/javascript">
alert("This alert box was called with the onload event");
</script>