BlackjackGame

/*
 Purpose: Simple "player-dealer" blackjack program to showcase the use of loops.
*/

import java.util.*;
import java.util.Scanner;

public class BlackjackGame
{

    private static void isWinner(int results)
    {
        switch (results) {
            case 21:
                System.out.println("Blackjack!");
                break;
            default:
                if (results >= 22) {
                    System.out.println("BUST! You lose.");
                } else if (results <= 20) {
                    System.out.println("UNDER! You lose.");
                } // end else if
        } // end switch
    } // end isWinner()

    private static int randomizer()
    {
        final int[] deck = new int[] {
                1,1,1,1,
                2,2,2,2,
                3,3,3,3,
                4,4,4,4,
                5,5,5,5,
                6,6,6,6,
                7,7,7,7,
                8,8,8,8,
                9,9,9,9,
                10,10,10,10,
                10,10,10,10,
                10,10,10,10,
                10,10,10,10,
                11,11,11,11};

        Random random = new Random();
        return deck[random.nextInt(deck.length)];
    } // end randomizer()

    private static int getSum(int a, int b)
    {
        return a + b;
    } // end getSum()

    private static void welcome()
    {
        System.out.println();
        System.out.println("**************************");
        System.out.println("Let's play Blackjack!");
    } // end welcome()

    private static String hitOrStand()
    {
        Scanner s = new Scanner(System.in);
        System.out.print("Do you want another card? ('y' to hit / 'n' to stand) ");
        String choice = s.nextLine();
        while (!(choice.equalsIgnoreCase("y") || choice.equalsIgnoreCase("n"))) {
            System.out.print("Invalid input. Please choose either Y or N only.");
            choice = s.nextLine();
        }
        return choice;
    }

    public static void main(String args[])
    {
        Scanner scan = new Scanner(System.in);
        char playAgain = 'y';
        final int NATURAL, BLACKJACK = 21;
        String choice = "";

        do {
            int firstCard = randomizer();
            int secondCard = randomizer();
            int newerCard = randomizer();
            int dealerOne = randomizer();
            int dealerTwo = randomizer();

            welcome();
            System.out.printf("\nDealer's cards: %d, %d\n",
                    dealerOne, dealerTwo);
            int dealerHand = getSum(dealerOne,dealerTwo);

            switch(dealerHand)
            {
                case 21:
                    System.out.println("Dealer wins!");
                    continue;

                /* The dealer will continue to take cards until they have
                   a total of 17 or higher.
                */
                default:
                    if (dealerHand <= 16) {
                        System.out.println("Dealer must take another card.");
                        int newDealerCard = randomizer();
                        System.out.printf("Dealer's third card: %d\n",newDealerCard);
                        System.out.printf("Total: %d\n",dealerHand += newDealerCard);

                        for (int i = 0; dealerHand < 17; i++) {
                            System.out.printf("Another card: %d\n", newDealerCard);
                            System.out.printf("Total so far: %d\n",
                                    dealerHand += newDealerCard);
                        }
                        if (dealerHand >= 17 && dealerHand < 21 || dealerHand > 21) {
                            System.out.println("Dealer stands.");
                        } // end inner if
                    } else if (dealerHand >= 17 && dealerHand != 21 || dealerHand > 21) {
                        System.out.printf("Dealer total: %d. Dealer stands..\n", dealerHand);
                    } else if (dealerHand == 21) {
                        System.out.printf("Dealer total: %d. Dealer wins.\n", dealerHand);
                    }
                    break;
            } // end switch

            System.out.printf("\nHere are your cards: %d, %d\n", firstCard,secondCard);
            int playerHand = getSum(firstCard,secondCard);
            System.out.printf("Total: %d\n", playerHand);
            switch (hitOrStand())
            {
                case "y":
                    System.out.printf("Here's your third card: %d\n", newerCard);
                    playerHand += newerCard;
                    System.out.printf("Total: %d\n", playerHand);
                    if (playerHand >= BLACKJACK) {
                        isWinner(playerHand); // skips while loop below
                        break;
                    }

                    while (hitOrStand().equalsIgnoreCase("y")) {
                        int anotherPlayerCard = randomizer();
                        System.out.printf("Here's another card: %d\n", anotherPlayerCard);
                        playerHand += anotherPlayerCard;
                        System.out.printf("Total: %d\n", playerHand);
                        if (playerHand >= BLACKJACK)
                            break;
                    } // end while

                    isWinner(playerHand);
                    break;
                case "n":
                    isWinner(playerHand);
                    break;
                default:
                    System.out.println("Invalid choice.");
                    break;
            } // end switch
            System.out.println();
            System.out.print("Do you want to play again? (y/n): ");
            playAgain = scan.next().charAt(0);
            while (!(playAgain == 'y' || playAgain == 'Y' ||
                    playAgain == 'n' || playAgain == 'N')) {
                System.out.print("Do you want to play again? (y/n): ");
                playAgain = scan.next().charAt(0);
            } // end while, input validation
        } while(!(playAgain == 'n'));
    } // end main
} // end class