HELP! "array required, but object found" :S

Question

Halo I'm new to Java and on one of my exercises I'm getting the following compile error and don't know why :S
"array required but Deck found"
Here is the code:
//Card.java this defines the Card class and object
public class Card {
private final int rank;
private final int suit;
// Kinds of suits
public final static int DIAMONDS = 1;
public final static int CLUBS = 2;
public final static int HEARTS = 3;
public final static int SPADES = 4;
// Kinds of ranks
public final static int ACE = 1;
public final static int DEUCE = 2;
public final static int THREE = 3;
public final static int FOUR = 4;
public final static int FIVE = 5;
public final static int SIX = 6;
public final static int SEVEN = 7;
public final static int EIGHT = 8;
public final static int NINE = 9;
public final static int TEN = 10;
public final static int JACK = 11;
public final static int QUEEN = 12;
public final static int KING = 13;
public Card(int rank, int suit) {
assert isValidRank(rank);
assert isValidSuit(suit);
this.rank = rank;
this.suit = suit;
public int getSuit() {
return suit;
public int getRank() {
return rank;
public static boolean isValidRank(int rank) {
return ACE <= rank && rank <= KING;
public static boolean isValidSuit(int suit) {
return DIAMONDS <= suit && suit <= SPADES;
public static String rankToString(int rank) {
switch (rank) {
case ACE:
return "Ace";
case DEUCE:
return "Deuce";
case THREE:
return "Three";
case FOUR:
return "Four";
case FIVE:
return "Five";
case SIX:
return "Six";
case SEVEN:
return "Seven";
case EIGHT:
return "Eight";
case NINE:
return "Nine";
case TEN:
return "Ten";
case JACK:
return "Jack";
case QUEEN:
return "Queen";
case KING:
return "King";
default:
return null;
public static String suitToString(int suit) {
switch (suit) {
case DIAMONDS:
return "Diamonds";
case CLUBS:
return "Clubs";
case HEARTS:
return "Hearts";
case SPADES:
return "Spades";
default:
return null;
// Deck.java creates a deck of cards:P
import java.util.*;
public class Deck {
public static int numSuits = 4;
public static int numRanks = 13;
public static int numCards = numSuits * numRanks;
public Card[][] cards;
public Deck() {
cards = new Card[numSuits][numRanks];
for (int suit = Card.DIAMONDS; suit <= Card.SPADES; suit++) {
for (int rank = Card.ACE; rank <= Card.KING; rank++) {
cards[suit-1][rank-1] = new Card(rank, suit);
public Card getCard(int suit, int rank) {
return cards[suit-1][rank-1];
//AND finally, DisplayDeck.java that creates a deck of cards and display the cards of a deck:P
import java.util.*;
public class DisplayDeck {
public static void main(String[] args) {
Deck bobbysDeck = new Deck();
for (int suit = Card.DIAMONDS; suit <= Card.SPADES; suit++) {
for (int rank = Card.ACE; rank <= Card.KING; rank++) {
System.out.format("%s of %s%n",
Card.rankToString(bobbysDeck[suit-1][rank-1].getrank()), //<---here is where I get the error
Card.suitToString(bobbysDeck[suit-1][rank-1].getsuit())); // <----and here too
bobbysDeck is an array, so why is it giving me this compile error? Thank you very much for your help.

Answer 1

For the benefit of others, here is Deck displayed with code tags:
public class Deck
  public static int numSuits = 4;
  public static int numRanks = 13;
  public static int numCards = numSuits * numRanks;
  public Card[][] cards;
  public Deck()
    cards = new Card[numSuits][numRanks];
    for (int suit = Card.DIAMONDS; suit <= Card.SPADES; suit++)
      for (int rank = Card.ACE; rank <= Card.KING; rank++)
        cards[suit - 1][rank - 1] = new Card(rank, suit);
  public Card getCard(int suit, int rank)
    return cards[suit - 1][rank - 1];
}You'll see that Deck holds an array of Card objects in its cards field. You could if you desired directly access that field and use that as an array like so:
  public static void main(String[] args)
    Deck bobbysDeck = new Deck();
    for (int suit = Card.DIAMONDS; suit <= Card.SPADES; suit++)
      for (int rank = Card.ACE; rank <= Card.KING; rank++)
        Card card = bobbysDeck.cards[suit - 1][rank - 1];
        System.out.format("%s of %s%n",
            Card.rankToString(card.getRank()),
            Card.suitToString(card.getSuit()));
  }but this allows outside classes to mess around with the innards of the Deck class in ways that we cannot control and can cause nasty bugs to appear that are very hard to identify and remove. Some class could for instance delete all the Card objects in cards. Much better and much safer is to make Deck's card variable a private variable and to only get the information through public methods, methods that allow the Deck class to control access. Notice that with this method, we can only get the card information; we can't delte or change it. So better is this:
  public static void main(String[] args)
    Deck bobbysDeck = new Deck();
    for (int suit = Card.DIAMONDS; suit <= Card.SPADES; suit++)
      for (int rank = Card.ACE; rank <= Card.KING; rank++)
        Card card = bobbysDeck.getCard(suit, rank);
        System.out.format("%s of %s%n",
            Card.rankToString(card.getRank()),
            Card.suitToString(card.getSuit()));
  }