<!DOCTYPE html>
<html>
<head>
<title>Single-line JavaScript Comments</title>
</head>
<body>
<h2 id="myHeading"></h2>
<p id="myParagraph"></p>
<script>
// For heading
document.getElementById("myHeading").innerHTML = "Single-line JavaScript Comments";
// For paragraph
document.getElementById("myParagraph").innerHTML = "I have comments in my JavaScript code!";
</script>
</body>
</html>