Question

I’m trying to add Cards to ArrayList deck, but it doesn’t seem to work(most of the code is an example on oracle.com ). I’m probably doing something really stupid, but I can’t seem to find it.. this is the code:

public class Card {

    public enum Rank 
    {
        DEUCE, THREE, FOUR, FIVE, SIX, SEVEN, EIGHT, NINE,
        TEN, JACK, QUEEN, KING, ACE
    }

    public enum Suit
    {
        HEARTS, DIAMONDS, SPADES, CLUBS
    }

    private final Rank rank;
    private final Suit suit;
    private static final List<Card> deck = new ArrayList<Card>();

    public Card(Rank rank, Suit suit)
    {
        this.suit = suit;
        this.rank = rank;
    }
    // initializes deck
    public void initDeck()
    {
        for (Suit suit : Suit.values())
        {
            for (Rank rank : Rank.values())
            {
                deck.add(new Card(rank, suit));
            }
        }
    }
    // returns a copy of the deck    
    public static ArrayList<Card> newDeck()
    {
        return new ArrayList<Card>(deck);
    }

    public Rank getRank()
    {
        return rank;
    }

    public Suit getSuit()
    {
        return suit;
    }

    public String toString()
    {
        return rank +" of "+ suit;
    }

    public static void main(String[] args)
    {
        System.out.println(deck.toString());
    }

}

Answer 1

Your problem is that you never actually invoke initDeck, so the deck remains empty, as it was when the static initializer ran:

private static final List<Card> deck = new ArrayList<Card>();

Other problems:

1. initDeck() is an instance method, but deck is a static reference.
2. initDeck() is a method on Card.
3. deck is a static member of Card, but a card does not own or define a deck.
4. newDeck is nonsensical in the face of a static final deck.
5. Cards should not be delivering decks anyway.

In short, your design is messed up – you need to think more and harder about the entities and their inter-relationships.