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Using the DeckOfCards class

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• Using the DeckOfCards class
  • Look only at the public things in the DeckOfCards class:

    public class DeckOfCards { public static final int NCARDS = 52; public DeckOfCards( ) ... public void shuffle(int n) ... public Card deal() ... public String toString() ... }

    From the definitions of the public methods, we can tell how to use them

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  • The constant value NCARDS:

    Because the definition contains the keyword static: public static final int NCARDS = 52; it is a class constant and the syntax used to refer to NCARDS is: DeckOfCards.NCARDS

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  • The constructor DeckOfCards( ):

    We know that a constructor is used to initialized a newly created Card object From its definition, we know this particular constructor takes no parameters Example usage: DeckOfCards x; x = new DeckOfCards( ); // One new deck of cards...

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  • The method void shuffle(int n)

    We know that it is an instance method (Because it does not have the keyword static Therefore, the shuffle() method must be invoked using an DeckOfCards object variable, like this: DeckOfCards x; x = new DeckOfCards( ); // Creates a DeckOfCards object x.shuffle(1000) // (shuffle() has one int type parameter)

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  • The method Card deal()

    We know that it is an instance method (Because it does not have the keyword static Therefore, the deal() method must be invoked using an DeckOfCards object variable, like this: DeckOfCards x; x = new DeckOfCards( ); x.deal() // (deal() has no parameters) Because the method deal() returns an Card object, we need to stored the return value in an Card typed variable: DeckOfCards x; Card r; x = new DeckOfCards( ); r = x.deal() // Store the card dealt in R

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  • Example Java program showing how to use the DeckOfCards class:

    public class TestDeck { public static void main(String[] args) { DeckOfCards a; a = new DeckOfCards(); System.out.println(a); // What a new deck look like System.out.println("Shuffle cards...."); a.shuffle(1000); // Shuffle deck of card "a" System.out.println(a); // Deck after shuffling Card b; b = a.deal(); System.out.println("Deal a card: " + b); b = a.deal(); System.out.println("Deal a card: " + b); b = a.deal(); System.out.println("Deal a card: " + b); b = a.deal(); System.out.println("Deal a card: " + b); b = a.deal(); System.out.println("Deal a card: " + b); } }

    Output 1:

    Ad 2d 3d 4d 5d 6d 7d 8d 9d 10d Jd Qd Kd Ac 2c 3c 4c 5c 6c 7c 8c 9c 10c Jc Qc Kc Ah 2h 3h 4h 5h 6h 7h 8h 9h 10h Jh Qh Kh As 2s 3s 4s 5s 6s 7s 8s 9s 10s Js Qs Ks Shuffle cards.... Ac Ah 6s Qh 6h Jh Ad 5c 7c 10d 8c Js 9d Qc Ks 10c 10h Qs Qd 4c 9s 3h 8s 5d 10s 3s 3d 2h 6d 3c 5s 2c 9h Jc Jd 7d 5h 8h Kc 6c 2d 4h 9c 7s 8d 4d Kh As Kd 7h 2s 4s Deal a card: Ac Deal a card: Ah Deal a card: 6s Deal a card: Qh Deal a card: 6h

    Output 1:

    Ad 2d 3d 4d 5d 6d 7d 8d 9d 10d Jd Qd Kd Ac 2c 3c 4c 5c 6c 7c 8c 9c 10c Jc Qc Kc Ah 2h 3h 4h 5h 6h 7h 8h 9h 10h Jh Qh Kh As 2s 3s 4s 5s 6s 7s 8s 9s 10s Js Qs Ks Shuffle cards.... 7h Kc Ac 9c 7d 10s Ah 4d 4c Jh Ad 3d 2c Kd 10c 2h 3s 6h 5s 2d 7s 8s 6c Qs 9s Js 9d Jd 3h Qc Jc 6d 2s 10d 8c 5c 3c Ks Qd 6s 8h As Kh 8d 10h 5h Qh 7c 4s 5d 9h 4h Deal a card: 7h Deal a card: Kc Deal a card: Ac Deal a card: 9c Deal a card: 7d

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  • Example Program: (Demo above code)                                                
    • The Card.java Prog file: click here
    • The DeckOfCards.java Prog file: click here
    • The TestDeck.java Prog file: click here

    How to run the program:

    Right click on links and save in a scratch directory To compile:   javac TestDeck.java To run:          java TestDeck