actionscript 3.0 how to incorporate algorithm to my code? - actionscript-3

Question

I am new to actionscript 3.0 and I am trying to make a deck of cards shuffle, I have succeeded with this but my problem is that my cards are being repeated, so I have duplicates of the same card in a 52 card deck after shuffling. I am trying to create a texas holdem game.
I found this discussion Randomize or shuffle an array but it does not tell me how to incorporate the Fisher–Yates algorithm into my code. I have tried several different methods suggested here and else where over the web and nothing is working (Think the problem is defiantly my lack of experience).
Can someone please give me an example of how to incorporate this into my code or a link to somewhere that will explain how to do this correctly.
Thanks in advance.
Paul
package src.CardDeck
{
public class CardDeck
{
public var allCards:Array = [];
public var cardNames:Array;
public var cardValues:Array;
public var gameType:String;
public var drawnCards:uint = 0;
public function CardDeck(game:String)
{
gameType = game;
cardNames = ["Ace","Two","Three",
"Four","Five","Six",
"Seven","Eight","Nine",
"Ten","Jack","Queen","King"];
if(gameType == "texasholdem")
{
cardValues = [1,2,3,4,5,6,7,8,9,10,10,10,10];
}
makeSuit("Spade");
makeSuit("Heart");
makeSuit("Diamond");
makeSuit("Club");
}
private function makeSuit(suitString:String):void
{
var card:Object;
for(var i:uint = 0; i < cardNames.length; i++)
{
card = {};
card.cardType = suitString;
card.cardName = cardNames[i];
card.cardValue = cardValues[i];
card.isDrawn = false;
allCards.push(card);
}
}
public function shuffle():Array
{
var shuffledArray:Array = [allCards.length];
var randomCard:Object;
do
{
randomCard = getRandomCard();
if(shuffledArray.indexOf(randomCard) == -1)
{
shuffledArray.push(randomCard);
}
}
while(shuffledArray.length < allCards.length)
return shuffledArray;
}
private function getRandomCard():Object
{
var randomIndex:int = Math.floor(Math.random()* allCards.length);
return allCards[randomIndex];
}
}
}

Answer 1

Bug Note:
var shuffledArray:Array = [allCards.length];
Makes an array with a single element which shuffledArray[0] = allCards.length.
In fact you do not need to pre allocate it just say:
var shuffledArray: Array = [];
Here is the classical Fisher–Yates version:
public function shuffleFisherYates():Array {
var shuffledArray:Array = [];
var randomCardIndex: int;
do {
randomCardIndex = Math.floor(Math.random()* allCards.length);
shuffledArray.push(allCards[randomCardIndex]); // add to mix
allCards.splice(randomCardIndex,1); // remove from deck
}while(allCards.length); // Meaning while allCards.length != 0
return shuffledArray;
}
Here is Durstenfeld's (in place) version:
public function shuffleDurstenfeld():Array {
var swap:Object;
var countdown:int = allCards.length-1;
var randomCardIndex: int;
for(i = countdown; i > 0; i--){
randomCardIndex = Math.floor(Math.random()* countdown);
swap = allCards[countdown];
allCards[countdown] = allCards[randomCardIndex];
allCards[randomCardIndex]= swap;
}
return allCards; // shuffled in place
}

Answer 2

Assuming your shuffling code is okay, I think a reason why you are seeing repeated cards is that within your getRandomCard() method, you are not accounting for cards that have been drawn. You randomly generate an index and return the card there in the array....but that card is still in the array and it's possible that same index can be randomly generated again, resulting in the same card being returned.