I can't get my card objects to print correctly

Question

This is the method I'm trying to display which is supposed to be a 4x4 grid of cards. I feel like there is something wrong possible inside the card objects? This is what I get when i try to run what's in printHiddenCard.

edu.cpp.cs.cs141.memgame.QCard@182decdb 
edu.cpp.cs.cs141.memgame.StarCard@26f0a63f 
edu.cpp.cs.cs141.memgame.PercCard@4361bd48 
edu.cpp.cs.cs141.memgame.PercCard@4361bd48 
edu.cpp.cs.cs141.memgame.MinusCard@53bd815b 
edu.cpp.cs.cs141.memgame.MinusCard@53bd815b 
edu.cpp.cs.cs141.memgame.PoundCard@2401f4c3 
edu.cpp.cs.cs141.memgame.QCard@182decdb 
edu.cpp.cs.cs141.memgame.SlashCard@7637f22 
edu.cpp.cs.cs141.memgame.ExclCard@4926097b 
edu.cpp.cs.cs141.memgame.StarCard@26f0a63f 
edu.cpp.cs.cs141.memgame.PlusCard@762efe5d 
edu.cpp.cs.cs141.memgame.PlusCard@762efe5d 
edu.cpp.cs.cs141.memgame.SlashCard@7637f22 
edu.cpp.cs.cs141.memgame.ExclCard@4926097b 
edu.cpp.cs.cs141.memgame.PoundCard@2401f4c3



private static int rows = 4;
private static int columns = 4;
    public static Card[][] card = new Card[rows][columns];

 public Card[][] printHiddenCard() {

    QCard c1 = new QCard();
    StarCard c2 = new StarCard();
    MinusCard c3 = new MinusCard();
    PoundCard c4 = new PoundCard();
    ExclCard c5 = new ExclCard();
    PercCard c6 = new PercCard();
    SlashCard c7 = new SlashCard();
    PlusCard c8 = new PlusCard();

    List<Card> allCards = Arrays.asList(c1, c2, c3, c4, c5, c6, c7, c8);
    List<Card> list = new ArrayList<>(allCards);
    list.addAll(allCards);
    Collections.shuffle(list);

    int counter = 0;
    for (int i = 0; i < rows; i++) {
        for (int j = 0; j < columns; j++) {
            card[i][j] = list.get(counter++);
            System.out.println(card[i][j] + " ");
        }
    }
    return card;
}

This is what one of the card objects look like:

public class QCard extends Card {

public QCard() {
    super("?");
}

}

And this is the superclass:

public abstract class Card {

private String cardType = "";
private boolean isFlipped = false;

public Card(String cardType) {
    this.cardType = cardType;
}

public String getCardType() {
    return cardType;
}

public boolean isFlipped() {
    return isFlipped;
}

public void setFlipped(boolean isFlipped) {
    this.isFlipped = isFlipped;
}

}

Answer 1

You should override the toString() method in the object you want to print, like this:

public class QCard extends Card {
    public QCard() {
        super("?");
    }

    public String toString() {
        return "card data";
    }
}

The above example will always print card data , so add the fields you want to include in your printOut.

Answer 2

Like @Molske, you need to override the toString() method. I suggest using the @Override annotation. Also take a look at How to override toString() properly in Java?

The toString() method belongs inside the QCard class.

public class QCard extends Card {
    public QCard() {
        super("?");
    }

    public String toString() {
        return this.cardType; //as long as that's all you need, this will do.
    }
}

Answer 3

Every Object you create in Java extends from Object. Every object, has a toString method. That is why you can literally put anything inside System.Out.println(Object) . Anything that goes in there it will print whatever is specified in your toString() method. For a new class it is not specified, so it will print out the class name with the hashcode. So, you will need to override the toString method in your Card class only and every derived class will do the same. Here is an example of how to modify this here .