<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>JavaScript Null Data Type</title>
</head>
<body>
<script>
var a = null;
document.write(a + "<br>"); // Print: null
var b = "Hello World!"
document.write(b + "<br>"); // Print: Hello World!
b = null;
document.write(b) // Print: null
</script>
</body>
</html>