JavaScript can be implemented using JavaScript statements that are placed within the <script>... </script>
</script>. <script ...> JavaScript code </script>
Example
HTML comment is added in the <script> tag, which is optional −
<html>
<body>
<script>
<!--
document.write("Hello World!")
//-->
</script>
</body>
</html>Added an optional HTML comment above that surrounds our JavaScript code. Yes, it is considered as a best practice, since this is to save our code from a browser that does not support JavaScript.
The comment ends with a "//-->". Here "//" signifies a comment in JavaScript, so we add that to prevent a browser from reading the end of the HTML comment as a piece of JavaScript code.