New to Java

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.