timw4mail/prime.html

## prime.html
<!DOCTYPE html>
<html>
<head>
	<title>JS Prime Generator</title>
</head>
<body>
	<div id="res"></div>
	<button id="generate">Generate more primes!</button>
	<script type="text/javascript">
	(function(){
		"use strict";

		//Add event listener to the button
		document.getElementById("generate").addEventListener("click", get_primes, false);

		var timeDiff  =  {
			setStartTime:function ()
			{
				var d = new Date();
				this.time  = d.getTime();
			},
			getDiff:function ()
			{
				var d2 = new Date();
				return (d2.getTime()-this.time);
			}
		};

		function get_primes()
		{
			//Start the timer
			timeDiff.setStartTime();

			//Define primes array
			var primes = [];

			//Check for "primes" key in localstorage
			if(localStorage.getItem("primes") != null)
			{
				var existing_primes = JSON.parse(localStorage.getItem("primes"));
				var num_primes = existing_primes.length;

				// If there is a "primes" key in localstorage, add it to the
				// primes array
				for(var i=0;i< num_primes;i++)
				{
					primes.push(existing_primes[i]);
				}
			}
			else //Seed the prime generator with the first prime number
			{
				primes.push(2);
			}

			// Get the largest existing prime, and add one
			// to make it the starting number in the search for the next prime
			var start_num = primes[primes.length - 1] + 1;

			// Specify a sane ending point
			var end_num = 999 + start_num;

			// Speed it up a tad
			if(start_num % 2 === 0)
			{
				start_num++;
				end_num++;
			}

			// Flag for determining if a number is prime
			var is_prime = true;
			var x = 0;

			for(i = start_num;i < end_num;i+=2)
			{
				is_prime = true;

				num_primes = primes.length;

				for(x=0;x<num_primes;x++)
				{
					//If the remainder is 0, the number is a composite
					if(i % primes[x] === 0)
					{
						is_prime = false;
						break;
					}
				}

				// If the number is prime, add it to the primes array
				if(is_prime === true)
				{
					primes.push(i);
				}
			}

			//Save the array in localStorage for the next round(s)
			localStorage.setItem("primes", JSON.stringify(primes));

			var output = "";

			//String together all the primes
			output += primes.join(", ");

			output += '<br /><br />';

			var total_time = timeDiff.getDiff();

			output += 'Generated '+primes.length+' primes in '+(total_time / 1000)+' seconds.';

			document.getElementById('res').innerHTML = output;

			location.href="#generate";
		}
	}());
	</script>
	<button onclick="localStorage.setItem('primes', '[2]')">Start Over</button>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>JS Prime Generator</title>
	</head>
	<body>
	<div id="res"></div>
	<button id="generate">Generate more primes!</button>
	<script type="text/javascript">
	(function(){
	"use strict";

	//Add event listener to the button
	document.getElementById("generate").addEventListener("click", get_primes, false);

	var timeDiff = {
	setStartTime:function ()
	{
	var d = new Date();
	this.time = d.getTime();
	},
	getDiff:function ()
	{
	var d2 = new Date();
	return (d2.getTime()-this.time);
	}
	};

	function get_primes()
	{
	//Start the timer
	timeDiff.setStartTime();

	//Define primes array
	var primes = [];

	//Check for "primes" key in localstorage
	if(localStorage.getItem("primes") != null)
	{
	var existing_primes = JSON.parse(localStorage.getItem("primes"));
	var num_primes = existing_primes.length;

	// If there is a "primes" key in localstorage, add it to the
	// primes array
	for(var i=0;i< num_primes;i++)
	{
	primes.push(existing_primes[i]);
	}
	}
	else //Seed the prime generator with the first prime number
	{
	primes.push(2);
	}

	// Get the largest existing prime, and add one
	// to make it the starting number in the search for the next prime
	var start_num = primes[primes.length - 1] + 1;

	// Specify a sane ending point
	var end_num = 999 + start_num;

	// Speed it up a tad
	if(start_num % 2 === 0)
	{
	start_num++;
	end_num++;
	}

	// Flag for determining if a number is prime
	var is_prime = true;
	var x = 0;

	for(i = start_num;i < end_num;i+=2)
	{
	is_prime = true;

	num_primes = primes.length;

	for(x=0;x<num_primes;x++)
	{
	//If the remainder is 0, the number is a composite
	if(i % primes[x] === 0)
	{
	is_prime = false;
	break;
	}
	}

	// If the number is prime, add it to the primes array
	if(is_prime === true)
	{
	primes.push(i);
	}
	}

	//Save the array in localStorage for the next round(s)
	localStorage.setItem("primes", JSON.stringify(primes));

	var output = "";

	//String together all the primes
	output += primes.join(", ");

	output += '<br /><br />';

	var total_time = timeDiff.getDiff();

	output += 'Generated '+primes.length+' primes in '+(total_time / 1000)+' seconds.';

	document.getElementById('res').innerHTML = output;

	location.href="#generate";
	}
	}());
	</script>
	<button onclick="localStorage.setItem('primes', '[2]')">Start Over</button>
	</body>
	</html>