Keesus' two dimensional array

twoDimArray.js

//HaloGame has the title of a particular halo release
	  HaloGame = new Array("Halo", "Halo 2", "Halo 3", "Halo: ODST", "Halo: Reach");
	  
var haloYearDifferences = new Array (0, 3, 6, 8, 9);
var halo2YearDifferences = new Array (3, 0, 3, 5, 6);
var halo3YearDifferences = new Array (6, 3, 0, 2, 3);
var haloOdstYearDifferences = new Array (8, 5, 2, 0, 1);
var haloReachYearDifferences = new Array (9, 6, 3, 1, 0);

//creating a 2-dimensional array of years between releases
var timeSpan = new Array (
  haloYearDifferences,
  halo2YearDifferences,
  halo3YearDifferences,
  haloOdstYearDifferences,
  haloReachYearDifferences
);

          //creating a 2-dimensional array of years between releases
	  //timeSpan = new Array (
		//new Array (0, 3, 6, 8, 9),
		//new Array (3, 0, 3, 5, 6),
		//new Array (6, 3, 0, 2, 3),
		//new Array (8, 5, 2, 0, 1),
		//new Array (9, 6, 3, 1, 0)
		//);
		
		function getGame() 
		{
		//presents a list of Halo titles and gets a number corresponding 
		//to the chosen game
		
		var theGame = ""; //will hold the game title
		
		var gameMenu = "Please choose a game by typing a number: \n";
			gameMenu += "0) Halo \n";
			gameMenu += "1) Halo 2 \n";
			gameMenu += "2) Halo 3 \n";
			gameMenu += "3) Halo: ODST \n";
			gameMenu += "4) Halo: Reach \n";
			
			theGame = prompt(gameMenu);
			return theGame;
		}  //end getGame
		
		function main() {
		var output = "";
		var game1 = getGame();
		var game2 = getGame();
		//var result = timeSpan[game1][game2];
                // allYearDifferencesForGame1 is also an array
                var allYearDifferencesForGame1 = timeSpan[game1];
                var yearDifferenceBetweenGame1AndGame2 = allYearDifferencesForGame1[game2];
		output = "The time between " + HaloGame[game1];
		output += " and " + HaloGame[game2];
		output += " is " + result + " years.";
		alert(output);

		} //end main	
		
		main();



// Less involved example
var siblings = ['Bobby', 'Tony', 'Betsy', 'Kevin'];
var tony = siblings[1];
// tony now has the value of the item at index 1 : a string 'Tony'

var parents = ['Tony', 'Dee'];
var family = [siblings, parents];
// family is now a 2 dimensional array
var firstItemInFamily = family[0];
// firstItemInFamily is the exact same thing as siblings (so it's an array)
var you = firstItemInFamily[3];
// you is now the string 'Kevin'
// the shortcut you are using in the above code is family[0][3] which combines the two above steps