jeremyckahn/javascript_timing_demo.html

## javascript_timing_demo.html
<html>

	<head>

		<script type="text/javascript">

			// inits
			var loopLimit = 100000000,
				countLimit = 5,
				wait = 500;

			// Pointless function that exists only to waste time/CPU cycles.
			function countTo(limit){

				var start = new Date();

				for (var i = 0; i < limit; i++){
					var a = true;
				}

				write('countTo() completed in ' + (new Date() - start) + ' milliseconds.');

				return;
			}

			function write(str){

				document.getElementsByTagName('body')[0].innerHTML += str + '<br/>'
			}

			// Shows how setInterval works.
			function testInterval(callback){

				var count = 0,
					start = new Date();

				timeoutHandle = setInterval(function(){
					if (count++ >= countLimit){

						// Cancel our timeout, we don't want it to fire anymore.
						clearInterval(timeoutHandle);
						write('<b>--testInterval() completed in ' + (new Date() - start) + ' milliseconds.<br/></b>');
						callback && callback();
						return;
					}

					countTo(loopLimit)

				}, wait);
			}

			// Shows how setTimeout works.
			function testTimeout(callback){

				var count = 0,
					start = new Date();

				setTimeout(function(){
					if (count++ >= countLimit){
						write('<b>--testTimeout() completed in ' + (new Date() - start) + ' milliseconds.</b><br/>');
						callback && callback();
						return;
					}

					countTo(loopLimit)

					setTimeout(arguments.callee, wait)
				}, wait);
			}


		</script>

	</head>

	<body>

		<script type="text/javascript">

			write('Counting to ' + loopLimit + ' (this is the long running block of code).')
			write('The for loop is being run ' + countLimit + ' times for each test.');
			write('Each timer has a ' + wait + ' millisecond wait time.</br>');
			testInterval(testTimeout);

		</script>

	</body>

</html>
	<html>

	<head>

	<script type="text/javascript">

	// inits
	var loopLimit = 100000000,
	countLimit = 5,
	wait = 500;

	// Pointless function that exists only to waste time/CPU cycles.
	function countTo(limit){

	var start = new Date();

	for (var i = 0; i < limit; i++){
	var a = true;
	}

	write('countTo() completed in ' + (new Date() - start) + ' milliseconds.');

	return;
	}

	function write(str){

	document.getElementsByTagName('body')[0].innerHTML += str + '<br/>'
	}

	// Shows how setInterval works.
	function testInterval(callback){

	var count = 0,
	start = new Date();

	timeoutHandle = setInterval(function(){
	if (count++ >= countLimit){

	// Cancel our timeout, we don't want it to fire anymore.
	clearInterval(timeoutHandle);
	write('<b>--testInterval() completed in ' + (new Date() - start) + ' milliseconds.<br/></b>');
	callback && callback();
	return;
	}

	countTo(loopLimit)

	}, wait);
	}

	// Shows how setTimeout works.
	function testTimeout(callback){

	var count = 0,
	start = new Date();

	setTimeout(function(){
	if (count++ >= countLimit){
	write('<b>--testTimeout() completed in ' + (new Date() - start) + ' milliseconds.</b><br/>');
	callback && callback();
	return;
	}

	countTo(loopLimit)

	setTimeout(arguments.callee, wait)
	}, wait);
	}


	</script>

	</head>

	<body>

	<script type="text/javascript">

	write('Counting to ' + loopLimit + ' (this is the long running block of code).')
	write('The for loop is being run ' + countLimit + ' times for each test.');
	write('Each timer has a ' + wait + ' millisecond wait time.</br>');
	testInterval(testTimeout);

	</script>

	</body>

	</html>