basic-computer-games/94_War/java/War.java

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Scanner;

/**
 * Converted FROM BASIC to Java by Nahid Mondol.
 *
 * Based on Trevor Hobsons approach.
 */
public class War {

    private static final int CARD_DECK_SIZE = 52;
    private static int playerTotalScore = 0;
    private static int computerTotalScore = 0;
    private static boolean invalidInput;
    private static Scanner userInput = new Scanner(System.in);

    // Simple approach for storing a deck of cards.
    // Suit-Value, ex: 2 of Spades = S-2, King of Diamonds = D-K, etc...
    private static ArrayList<String> deckOfCards = new ArrayList<String>(
            Arrays.asList("S-2", "H-2", "C-2", "D-2", "S-3", "H-3", "C-3", "D-3", "S-4", "H-4", "C-4", "D-4", "S-5",
                    "H-5", "C-5", "D-5", "S-6", "H-6", "C-6", "D-6", "S-7", "H-7", "C-7", "D-7", "S-8", "H-8", "C-8",
                    "D-8", "S-9", "H-9", "C-9", "D-9", "S-10", "H-10", "C-10", "D-10", "S-J", "H-J", "C-J", "D-J",
                    "S-Q", "H-Q", "C-Q", "D-Q", "S-K", "H-K", "C-K", "D-K", "S-A", "H-A", "C-A", "D-A"));

    public static void main(String[] args) {
        introMessage();
        showDirectionsBasedOnInput();
        playGame();
    }

    private static void introMessage() {
        System.out.println("\t         WAR");
        System.out.println("CREATIVE COMPUTING  MORRISTOWN, NEW JERSEY");
        System.out.println("THIS IS THE CARD GAME OF WAR. EACH CARD IS GIVEN BY SUIT-#");
        System.out.print("AS S-7 FOR SPADE 7. DO YOU WANT DIRECTIONS? ");
    }

    private static void showDirectionsBasedOnInput() {
        // Stay in loop until player chooses an option.
        invalidInput = true;
        while (invalidInput) {
            switch (userInput.nextLine().toLowerCase()) {
                case "yes":
                    System.out.println("THE COMPUTER GIVES YOU AND IT A 'CARD'. THE HIGHER CARD");
                    System.out.println("(NUMERICALLY) WINS. THE GAME ENDS WHEN YOU CHOOSE NOT TO ");
                    System.out.println("CONTINUE OR WHEN YOU HAVE FINISHED THE PACK.\n");
                    invalidInput = false;
                    break;
                case "no":
                    System.out.println();
                    invalidInput = false;
                    break;
                default:
                    System.out.print("YES OR NO, PLEASE.   ");
            }
        }
    }

    private static void playGame() {

        // Checks to see if the player ends the game early.
        // Ending early will cause a different output to appear.
        boolean gameEndedEarly = false;

        // Shuffle the deck of cards.
        Collections.shuffle(deckOfCards);

        // Since the deck is already suffled, pull each card until the deck is empty or
        // until the user quits.
        outerloop:
        for (int i = 1; i <= CARD_DECK_SIZE; i += 2) {
            System.out.println("YOU: " + deckOfCards.get(i - 1) + "\t " + "COMPUTER: " + deckOfCards.get(i));
            getWinner(deckOfCards.get(i - 1), deckOfCards.get(i));

            invalidInput = true;
            while (invalidInput) {
                if (endedEarly()) {
                    // Player ended game early.
                    // Break out of game loop and show end game output.
                    gameEndedEarly = true;
                    break outerloop;
                }
            }
        }

        endGameOutput(gameEndedEarly);
    }

    /**
     * Outputs the winner of the current round.
     *
     * @param playerCard   Players card.
     * @param computerCard Computers card.
     */
    private static void getWinner(String playerCard, String computerCard) {

        // Return the number value of the card pulled.
        String playerCardScore = (playerCard.length() == 3) ? Character.toString(playerCard.charAt(2))
                : playerCard.substring(2, 4);
        String computerCardScore = (computerCard.length() == 3) ? Character.toString(computerCard.charAt(2))
                : computerCard.substring(2, 4);

        if (checkCourtCards(playerCardScore) > checkCourtCards(computerCardScore)) {
            System.out.println("YOU WIN.   YOU HAVE " + playerWonRound() + "   COMPUTER HAS " + getComputerScore());
        } else if (checkCourtCards(playerCardScore) < checkCourtCards(computerCardScore)) {
            System.out.println(
                    "COMPUTER WINS!!!   YOU HAVE " + getPlayerScore() + "   COMPUTER HAS " + computerWonRound());
        } else {
            System.out.println("TIE.  NO SCORE CHANGE");
        }

        System.out.print("DO YOU WANT TO CONTINUE? ");
    }

    /**
     * @param cardScore Score of the card being pulled.
     * @return an integer value of the current card's score.
     */
    private static int checkCourtCards(String cardScore) {
        switch (cardScore) {
            case "J":
                return Integer.parseInt("11");
            case "Q":
                return Integer.parseInt("12");
            case "K":
                return Integer.parseInt("13");
            case "A":
                return Integer.parseInt("14");
            default:
                return Integer.parseInt(cardScore);
        }
    }

    /**
     * @return true if the player ended the game early. false otherwise.
     */
    private static boolean endedEarly() {
        switch (userInput.nextLine().toLowerCase()) {
            case "yes":
                invalidInput = false;
                return false;
            case "no":
                invalidInput = false;
                return true;
            default:
                invalidInput = true;
                System.out.print("YES OR NO, PLEASE.   ");
                return false;
        }
    }

    /**
     * Show output based on if the game was ended early or not.
     *
     * @param endedEarly true if the game was ended early, false otherwise.
     */
    private static void endGameOutput(boolean endedEarly) {
        if (endedEarly) {
            System.out.println("YOU HAVE ENDED THE GAME. FINAL SCORE:  YOU: " + getPlayerScore() + " COMPUTER: "
                    + getComputerScore());
            System.out.println("THANKS FOR PLAYING.  IT WAS FUN.");
        } else {
            System.out.println("WE HAVE RUN OUT OF CARDS. FINAL SCORE:  YOU: " + getPlayerScore() + " COMPUTER: "
                    + getComputerScore());
            System.out.println("THANKS FOR PLAYING.  IT WAS FUN.");
        }
    }

    /**
     * Increment the player's total score if they have won the round.
     */
    private static int playerWonRound() {
        return playerTotalScore += 1;
    }

    /**
     * Get the player's total score.
     */
    private static int getPlayerScore() {
        return playerTotalScore;
    }

    /**
     * Increment the computer's total score if they have won the round.
     */
    private static int computerWonRound() {
        return computerTotalScore += 1;
    }

    /**
     * Get the computer's total score.
     */
    private static int getComputerScore() {
        return computerTotalScore;
    }
}