Thread: Problem with 2d array

Hi,

I am having trying to model a deck(s) of cards in Java and am having trouble with an array. I want to get a 2d array with the first set being the value of the card and the second being the suit.
If i leave it as a 1d array, just adding the card values, everthying works fine but when I try to change to 2d all I get is Null.pointerException and ArrayIndexOutOfBounds errors.

public class decks
{
    // instance variables - replace the example below with your own
    private int numberOfDecks;
    private int totalNoCards;
    private String cardArray[][];
    private String oneDeck[] = {"Two","Three","Four","Five","Six","Seven","Eight","Nine","Ten","Jack","Queen","King","Ace"};
    private String suits[] = {"Clubs","Spades","Hearts","Diamonds"};
    /**
     * Constructor for objects of class decks
     */
    public decks(int numberOfDecks)
    {
        // initialise instance variables
        this.numberOfDecks = numberOfDecks;
        this.totalNoCards = numberOfDecks * 52;
        cardArray = new String[0][totalNoCards];
 
    }
 
    /**
     * An example of a method - replace this comment with your own
     * 
     * @param  y   a sample parameter for a method
     * @return     the sum of x and y 
     */
 
    public void addCards() 
 
    {
        int counterOne = 1;
        int counterTwo = 0;
        int counterThree = 0;
        int counterFour = 0;
 
        while(counterOne <= numberOfDecks) {
            cardArray[0][counterTwo] = oneDeck[counterThree];
            counterTwo++;
            counterThree++;
            if(counterThree > 12) {
                counterFour++;
                counterThree = 0;
                if(counterFour > 3) {
                    counterFour = 0;
                    counterOne++;
                }
            }           
 
        }
    }
}

I am sure there is something simple I am missing. Any help is much appreciated.

Thankyou

Inspect the line where you create your array...you've initialized an array of an array, with the first array of length zero (it should be of length > 0)

 cardArray = new String[0][totalNoCards];