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Desiging a Poker Playing library: Overview

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• Functionality needed to play Poker
  • What do you need to play Poker:

    Information on the cards held by a player We can store this information using an array of Card object: Card[] player = new Card[5];          Operations to check the hand of a player Operations: isFlush( playerHand ): returns true is playerHand has a Flush, and returns false otherwise. isStraight( playerHand ): returns true is playerHand has a Straight, and returns false otherwise. is4s( playerHand ): returns true is playerHand has a Four Of a Kind, and returns false otherwise. isFullHouse( playerHand ): returns true is playerHand has a Full House, and returns false otherwise. And so on.... Operation to assign a value to the hand of a player valueHand( playerHand ) = a number that represents the strength of the playerHand The assigned value must be such that a better Poker hand is assigned a higher value !!! (So that we can simply compare the values (integer numbers) to find out which is the better Poker hand)

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• Representing a Player's (Poker) hand
  • As stated above, we will use an array of 5 Card objects

  • Example:

    public class TestPoker1 { public static void main(String[] args) { DeckOfCards a; Card[] player1 = new Card[5]; Card[] player2 = new Card[5]; int i; a = new DeckOfCards(); System.out.println(a); System.out.println("Shuffle cards...."); a.shuffle(1000); System.out.println(a); /* ============================= Deal cards to 2 players ============================= */ for ( i = 0; i < 5; i++ ) { player1[i] = a.deal(); player2[i] = a.deal(); } System.out.print("player1's hand: "); for ( i = 0; i < 5; i++ ) System.out.print( player1[i] + " "); System.out.println(); System.out.print("player2's hand: "); for ( i = 0; i < 5; i++ ) System.out.print( player2[i] + " "); System.out.println(); } }

    Sample output:

    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.... 9s 8s 3c 10h Qh 4s 7h Jh 5c 2s As Kc Ac Qc 4h Ah Qs 4d 8d 8h 10c 6c 6s Jd 10s Qd Ks 5d 5h 8c 7s 9c 4c 3h 9d Kh 2h 5s 3s 9h 6d 2d Ad 7c 6h 10d Kd 2c Js 3d 7d Jc player1's hand: 9s 3c Qh 7h 5c player2's hand: 8s 10h 4s Jh 2s

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  • Example Program: (Demo above code)                                                
    • The TestPoker1.java Prog file: click here
    • The Card.java Prog file: click here
    • The DeckOfCards.java Prog file: click here

    How to run the program:

    Right click on link and save in a scratch directory To compile:   javac TestPoker1.java To run:          java TestPoker1

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• A note of program design....
  • Some people will want to make a Poker hand into an object

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  • For example:

    public class PokerHand { private Card[] hand; public PokerHand() { hand = new Card[5]; } }

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  • There are advantages but also disadvantages to this approach...

    Advantage:

    Safer (because the instance variable hand has the private access quantifier) (You cannot easily switch cards from a Poker hand)

    Disadvantage:

    Increased complexity You need to define (many) methods inside the PokerHand class to maintain the private variables Example: To deal a card to a a player's hand, you would need to assign to the hand[] variable. For example: player1.hand[0] = a.deal(); Since the hand[] variable is private, you will need to define a public addCard() method inside the PokerHand class to deal a card to the player's hand.

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  • I decided to keep the programs simple

    That's why I use an array to represent a player's hand:

    Card[] player1 = new Card[5]; Card[] player2 = new Card[5];

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    It is not very safe...

    After dealing some cards:

    /* ============================= Deal cards to 2 players ============================= */ for ( i = 0; i < 5; i++ ) { player1[i] = a.deal(); player2[i] = a.deal(); }

    You can modify some of the cards in the hand easily:

    player1[0] = a.deal(); player2[2] = a.deal();

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  • The programs are much simpler as the result of this choice....

    (I think simplicity should be the prime concern in an introductory course)