Picking 7 Random "Cards"

Question

I am wondering if the following code would yield essentially the same results as dealing 7 cards from a sufficiently shuffled deck:

var deck:Array = new Array();

for(var j:int = 0;j<52;j++){

deck.push(j);

}

var hand:Array=new Array();

var card:uint;

for(j = 0;j<7;j++){

card = int(Math.random()*deck.length);

hand.push(deck.splice(card,1));

}

If not it would be great to know:

1. Why?

2. How to get the desired results.

Cheers,

John

Andrei1-bKoviI · Answer

This definitely works but just using Math.random() doesn't make it really random.

A more reliable approach from randomization standpoint is using some shuffling algorithm. The most common is Fisher-Yates algorithm. Function shuffle in the code below implements this.

So, this code makes it more random. I organized tasks in different functions.

var deck:Array;
makeDeck();
shuffleDeck();
deal();
function makeDeck():void
{
          deck = [];
          for (var i:int = 0; i < 52; i++)
                    deck.push(i);
}
function shuffleDeck():void
{
          shuffle(deck);
          trace(deck);
}
function deal():void
{
          var hand:Array = deck.splice(0, 7);
          trace(hand);
}
function shuffle(array:Array):void
{
          var i:int = array.length;
          var j:int;
          var temp:*;
          while (i--)
          {
                    j = Math.random() * i;
                    temp = array;
                    array = array;
                    array = temp;
          }
}

Message was edited by: Andrei1 Changed deal() function - just splice is sufficient.

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