timw4mail · October 18, 2011 17:54
diff --git a/prime.html b/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>