JS HISTORY LENGTH EXAMPLE
Run 
<!doctype html>
	<head>
		<title>JS History Length Example</title>
	</head>
	<body>
		<h3>History Length Property</h3>
		<script>
            // fetch number of visited pages
            let len = window.history.length
            document.write("You visited " +len+ " Pages.")
        </script>
	</body>
</html>