import java.util.Scanner;
import java.util.Vector;
/* Simulation of console-I/O program Blackjack,
using ConsoleApplet as a basis. See the file
ConsoleApplet.java for more information.
*/
public class BlackjackConsole
{
private static Scanner scanner = new Scanner(System.in);
private int[] deck; // An array of 52 Cards, representing the deck.
private int currentPosition; // Current position in the deck
private Vector hand; // The cards in the hand.
public static void main(String[] args)
{
new BlackjackConsole().run();
}
public void run()
{
/*
This program lets the user play Blackjack. The computer
acts as the dealer. The user has a stake of $100, and
makes a bet on each game. The user can leave at any time,
or will be kicked out when he loses all the money.
House rules: The dealer hits on a total of 16 or less
and stands on a total of 17 or more. Dealer wins ties.
A new deck of cards is used for each game.
*/
int money; // Amount of money the user has.
int bet; // Amount user bets on a game.
boolean userWins; // Did the user win the game?
System.out.println("Welcome to the game of blackjack.");
System.out.println();
money = 100; // User starts with $100.
while (true)
{
System.out.println("You have " + money + " dollars.");
do
{
System.out.println("How many dollars do you want to bet? (Enter 0 to end.)");
System.out.print("? ");
bet = scanner.nextInt();
if (bet < 0 || bet > money)
{
System.out.println("Your answer must be between 0 and " + money + '.');
}
} while (bet < 0 || bet > money);
if (bet == 0)
{
break;
}
userWins = playBlackjack();
if (userWins)
{
money = money + bet;
} else
{
money = money - bet;
}
System.out.println();
if (money == 0)
{
System.out.println("Looks like you've are out of money!");
break;
}
}
System.out.println();
System.out.println("You leave with $" + money + '.');
} // end main()
private boolean playBlackjack()
{
// Let the user play one game of Blackjack.
// Return true if the user wins, false if the user loses.
Vector dealerHand; // The dealer's hand.
Vector userHand; // The user's hand.
// Create an unshuffled deck of cards.
deck = new int[52];
int cardCt = 0; // How many cards have been created so far.
for (int suit = 0; suit <= 3; suit++)
{
for (int value = 1; value <= 13; value++)
{
deck[cardCt] = value;
cardCt++;
}
}
currentPosition = 0;
dealerHand = new Vector();
userHand = new Vector();
/* Shuffle the deck, then deal two cards to each player. */
shuffle();
dealerHand.addElement(dealCard());
dealerHand.addElement(dealCard());
userHand.addElement(dealCard());
userHand.addElement(dealCard());
System.out.println();
System.out.println();
/* Check if one of the players has Blackjack (two cards totaling to 21).
The player with Blackjack wins the game. Dealer wins ties.
*/
if (value(dealerHand) == 21)
{
System.out.println("Dealer has the " + showCard(getCard(dealerHand, 0)) + " and the " + showCard(getCard(dealerHand, 1)) + ".");
System.out.println("User has the " + showCard(getCard(userHand, 0)) + " and the " + showCard(getCard(userHand, 1)) + ".");
System.out.println();
System.out.println("Dealer has Blackjack. Dealer wins.");
return false;
}
if (value(userHand) == 21)
{
System.out.println("Dealer has the " + showCard(getCard(dealerHand, 0)) + " and the " + showCard(getCard(dealerHand, 1)) + ".");
System.out.println("User has the " + showCard(getCard(userHand, 0)) + " and the " + showCard(getCard(userHand, 1)) + ".");
System.out.println();
System.out.println("You have Blackjack. You win.");
return true;
}
/* If neither player has Blackjack, play the game. The user gets a chance
to draw cards (i.e., to "Hit"). The while loop ends when the user
chooses to "Stand" or when the user goes over 21.
*/
while (true)
{
/* Display user's cards, and let user decide to Hit or Stand. */
System.out.println();
System.out.println();
System.out.println("Your cards are:");
for (int i = 0; i < userHand.size(); i++)
{
System.out.println(" " + showCard(getCard(userHand, i)));
}
System.out.println("Your total is " + value(userHand));
System.out.println();
System.out.println("Dealer is showing the " + showCard(getCard(dealerHand, 0)));
System.out.println();
System.out.print("Hit (H) or Stand (S)? ");
char userAction; // User's response, 'H' or 'S'.
do
{
userAction = Character.toUpperCase(scanner.next().charAt(0));
if (userAction != 'H' && userAction != 'S')
{
System.out.print("Please respond H or S: ");
}
} while (userAction != 'H' && userAction != 'S');
/* If the user Hits, the user gets a card. If the user Stands, the
dealer gets a chance to draw and the game ends.
*/
if (userAction == 'S')
{
// Loop ends; user is done taking cards.
break;
} else
{ // userAction is 'H'.
// Give the user a card. If the user goes over 21, the user loses.
int newCard = dealCard();
userHand.addElement(newCard);
System.out.println();
System.out.println("User hits.");
System.out.println("Your card is the " + showCard(newCard));
System.out.println("Your total is now " + value(userHand));
if (value(userHand) > 21)
{
System.out.println();
System.out.println("You busted by going over 21. You lose.");
System.out.println("Dealer's other card was the " + showCard(getCard(dealerHand, 1)));
return false;
}
}
} // end while loop
/* If we get to this point, the user has Stood with 21 or less. Now, it's
the dealer's chance to draw. Dealer draws cards until the dealer's total is > 16.
*/
System.out.println();
System.out.println("User stands.");
System.out.println("Dealer's cards are");
System.out.println(" " + showCard(getCard(dealerHand, 0)));
System.out.println(" " + showCard(getCard(dealerHand, 1)));
while (value(dealerHand) <= 16)
{
int newCard = dealCard();
System.out.println("Dealer hits and gets the " + showCard(newCard));
dealerHand.addElement(newCard);
}
System.out.println("Dealer's total is " + value(dealerHand));
/* Now, the winner can be declared. */
System.out.println();
if (value(dealerHand) > 21)
{
System.out.println("Dealer busted by going over 21. You win.");
return true;
} else
{
if (value(dealerHand) == value(userHand))
{
System.out.println("Dealer wins on a tie. You lose.");
return false;
} else
{
if (value(dealerHand) > value(userHand))
{
System.out.println("Dealer wins, " + value(dealerHand) + " points to " + value(userHand) + ".");
return false;
} else
{
System.out.println("You win, " + value(userHand) + " points to " + value(dealerHand) + ".");
return true;
}
}
}
} // end playBlackjack()
public int dealCard()
{
// Deals one card from the deck and returns it.
if (currentPosition == 52)
{
shuffle();
}
currentPosition++;
return deck[currentPosition - 1];
}
public void shuffle()
{
// Put all the used cards back into the deck, and shuffle it into
// a random order.
for (int i = 51; i > 0; i--)
{
int rand = (int) (Math.random() * (i + 1));
int temp = deck[i];
deck[i] = deck[rand];
deck[rand] = temp;
}
currentPosition = 0;
}
public int getCard(Vector hand, int position)
{
// Get the card from the hand in given position, where positions
// are numbered starting from 0. If the specified position is
// not the position number of a card in the hand, then null
// is returned.
if (position >= 0 && position < hand.size())
{
return ((Integer)hand.elementAt(position)).intValue();
} else
{
return 0;
}
}
public int value(Vector hand)
{
// Returns the value of this hand for the
// game of Blackjack.
int val; // The value computed for the hand.
boolean ace; // This will be set to true if the
// hand contains an ace.
int cards; // Number of cards in the hand.
val = 0;
ace = false;
cards = hand.size();
for (int i = 0; i < cards; i++)
{
// Add the value of the i-th card in the hand.
int card; // The i-th card;
int cardVal; // The blackjack value of the i-th card.
card = getCard(hand, i);
cardVal = getCardValue(card); // The normal value, 1 to 13.
if (cardVal > 10)
{
cardVal = 10; // For a Jack, Queen, or King.
}
if (cardVal == 1)
{
ace = true; // There is at least one ace.
}
val = val + cardVal;
}
// Now, val is the value of the hand, counting any ace as 1.
// If there is an ace, and if changing its value from 1 to
// 11 would leave the score less than or equal to 21,
// then do so by adding the extra 10 points to val.
if (ace == true && val + 10 <= 21)
{
val = val + 10;
}
return val;
}
public int getCardValue(int card)
{
int result = card;
switch (card)
{
case 11:
case 12:
case 13:
result = 10;
}
return result;
}
public String showCard(int card)
{
switch (card)
{
case 1:
return "Ace";
case 2:
return "2";
case 3:
return "3";
case 4:
return "4";
case 5:
return "5";
case 6:
return "6";
case 7:
return "7";
case 8:
return "8";
case 9:
return "9";
case 10:
return "10";
case 11:
return "Jack";
case 12:
return "Queen";
case 13:
return "King";
default:
return "??";
}
}
} // end class