BlackJack Console

Objectives

1. Reuse (copy) code from another project into a current project.
2. Use a set of custom classes to create a rudimentary application program.

Advanced

1. Extend the functionality of an existing codebase to handle a more complex approach to the application.

Introduction

Blackjack, also known as "twenty-one", is a casino card game in which a player attempts to build a hand that is closer to a score of 21 than the house (or dealer's) hand without going over a total of 21 (or "busting"). The Ace's base value is one (1), but can be used as a value of eleven (11) if doing so does not bust a hand. Players are initially dealt two cards and choose to be dealt additional cards (to "hit") or to hold their hand until the end of the round (to "stay").

In this exercise, we're going to set up a player class that has knowledge of how to play Blackjack. That means it will need to be able to score its own hand and decide whether to hit or stay. We'll then create a class that can execute a Blackjack game between the house and a single player.

Instructions

Fork and clone this lab.

I. Set Up The Class Files

A. Reuse FISCard and FISCardDeck from OOP-Cards-Model

This lab reuses the FISCard and FISCardDeck classes created in the OOP-Cards-Model lab. Find a way to bring your code for those classes into your BlackJack project. You'll need to add them to your Xcode project by selecting File --> Add Files to "BlackJack" or dragging them in. Make sure to check "Copy files if needed" so they are added to your Blackjack repository -- you'll want to commit them along with your Blackjack solution!

B. Create Additional Class Files

Before we can run the testing suite we need to set up two new classes: FISBlackjackGame and FISBlackjackPlayer. Create these class files now.

1. In FISBlackjackGame.h, import FISBlackjackPlayer.h and FISCardDeck.h. Then,

• Create three properties:
  • a FISCardDeck called deck,
  • a FISBlackjackPlayer called house, and
  • a FISBlackjackPlayer called player.
• And declare the following methods:
  • playBlackjack which provides no return,
  • dealNewRound which provides no return,
  • dealCardToPlayer which provides no return,
  • dealCardToHouse which provides no return,
  • processPlayerTurn which provides no return,
  • processHouseTurn which provides no return,
  • houseWins, which returns a BOOL,
  • incrementWinsAndLossesForHouseWins: which takes one argument, a BOOL called houseWins, and provides no return.

2. To get things compiling, add empty implementations for all the void methods in FISBlackjackGame.m, and have houseWins return NO; for now.

3. In FISBlackjackPlayer.h, import FISCard.h. Then,

• Create an NSString property called name; and
• Create an NSMutableArray called cardsInHand; and
• Create four BOOL properties:
  • aceInHand,
  • blackjack,
  • busted, and
  • stayed;
• Create three NSUInteger properties:
  • handscore, and
  • wins, and
  • losses; and
• Declare the following methods:
  • a designated initializer which takes one argument for the name property,
  • resetForNewGame which provides no return,
  • acceptCard: which takes one argument, a FISCard called card, and provides no return, and
  • shouldHit which returns a BOOL.

4. To get things compiling, let's add some minimal method implementations in FIBlackjackPlayer.m. Define the designated initializer to call [super init];, the void methods resetForNewGame and acceptCard: to empty implementations, and shouldHit to return NO.

5. At this point, the test suite should successfully build. Go ahead and run the tests to check for initial failures. If you have any errors, double-check your set up. If you successfully copied your implementations of FISCard and FISCardDeck, then all of the tests on those classes should already succeed.

II. Implement FISBlackjackPlayer

Before we can write the logic for the blackjack game, we need to tell the players how to play.

1. Let's start at the beginning of the class's lifecycle by filling out the designated initializer. It should:

• use the name argument to initialize the name property,
• initialize the mutable array to an empty mutable array,
• set the integers to zero, and
• set the booleans to NO.

2. Override the default initializer (init) to call the designated initializer with an empty string submitted as the name argument.

3. Next, let's teach our player class how to accept a card and update the game state. We're going to want to do this whenever a card is added to the hand, which happens in acceptCard:. That method should add the incoming card to cardsInHand and update the score. This is a surprisingly complicated process. Let's break it down.

4. After adding a new card in acceptCard:, we need to update the handscore to the total of the cardValue property of all the cards in the cardsInHand array.

5. Now let's add functionality to detect an Ace and adjust the score accordingly. Find a way to determine if the cardsInHand array contains an Ace and set the aceInHand boolean to YES if it does. Then, if the total value of the cards in the hand is eleven or less, add ten points to the score. This, effectively, is teaching the player to use the Ace as a "soft eleven" when doing so will not cause a bust, but teaching it to use the Ace as a "hard one" otherwise.

6. Now we should give the player an ability to determine when its hand is a "blackjack" (exactly two cards with a score of 21) or is "busted" (a score of 22 or higher). * If a hand is a blackjack, we should set the blackjack property to YES. * We should set the busted property to YES if the handscore is greater than 21.

All of the tests for acceptCard: should pass before you move on.

4. Write the implementation for the shouldHit method. This is where the player decides whether to accept a new card ("to hit") or stop at its current score until the end of the game ("to stay"). After staying, the player cannot take a new card for the rest of the current game. A simple implementation of the decision making method is to just have the player follow "house rules": which is to say that the house is required to openly declare at what score it will stay—typically either 16 or 17. If the handscore is greater than that value, set the stayed property to YES and return NO, otherwise return YES.

5. Write the implementation for the resetForNewGame which resets a player for a new game. It should:

• empty the cardsInHand array,
• set handscore to zero, and
• set the four boolean values (aceInHand, stayed, blackjack, and busted) to NO.
• It should not affect the wins and losses integers.

9. Lastly, override the description method to provide a customized printout in the debug console. Hint: This is a great time to use NSMutableString. Because of randomization, the test for this method is simply looking that this string contains substrings that match each the property names, so it is somewhat up to you to decide how to present the information. Remember that you can format line breaks with \n and indentations with spaces.

Consider the following console output when formatting your description string:

2015-10-02 15:48:32.953 BlackJack[9872:367674] FISBlackjackPlayer:
  name: Player
  cards: ♠A ♠J
  handscore  : 21
  ace in hand: 1
  stayed     : 1
  blackjack  : 1
  busted     : 0
  wins  : 2
  losses: 0

Use the FISAppDelegate's application:didFinishLaunchingWithOptions: method to create an instance of FISBlackjackPlayer with your own name and NSLog() its description string. You can initialize an instance of FISCardDeck and use its drawNextCard method to pass your player a card using its acceptCard: method. Remember to use ⌘ R to run the scheme instead of the tests.

II. Implement FISBlackjackGame

Now that we've taught our FISBlackjackPlayer class how to play Blackjack, let's set up the game. As you may infer from how we set up the class file, it's the game that will be responsible for holding the deck and dealing the cards to the two players house and player (in Blackjack, all players play individually against the house).

1. Start by overriding FISBlackjackGame's default initializer (init). Its properties should be set to:

• a default instance of FISCardDeck,
• an instance of FISBlackjackPlayer with the name @"House", and
• an instance of FISBlackjackPlayer with the name @"Player".

2. Next, write the implementations for dealCardToPlayer and dealCardToHouse. They should use FISCardDeck's drawNextCard method to get the next card from the deck, and use FISBlackjackPlayer's acceptCard: method to pass the card to the respective player.

3. Write the implementation for dealNewRound. This is the first deal of a new game which provides two cards to each player. Remember that cards should be dealt one at a time to all players in a round.

4. Now write the implementations for the processPlayerTurn and processHouseTurn methods. In blackjack, a player may hit (get dealt a new card) if they have not busted nor stayed. But, they choose to either hit or stay. (Hint: Can you use the boolean properties of the player and the house to evaluate their permission to hit? Also, remember that we set up a shouldHit method on the player class.)

5. Now write the implementation for the houseWins method. This returns a boolean of whether or not the house has won (you may treat a "push", which is when both the player and the house have blackjack hands, as a loss for the house). Keep in mind that if the house has busted, the player wins. If the player has busted, then the house wins. And the player only wins with a score that exceeds the house's score (the house wins ties).

6. Write the implementation for incrementWinsAndLossesForHouseWins:. Evaluate the argument boolean. If the house has won, then add one to the house's wins property and to the player's losses property. However, if the house has not won, then add one to the house's losses property and to the player's wins property. Add an NSLog() message for each case so you can see the result of the hand in the debug console.

7. At this point, all of the tests should be passing. You've written all the logic for the individual steps of playing Blackjack! Now, put them together inside the playBlackjack method.

• Start by resetting the deck and telling the players to start a new game.
• Then, deal a new round (dealNewRound).
• Since some Blackjack rules allow a hand limit of five cards, create a loop with a maximum of three iterations. Within the loop, give the player its turn, and then the house. Keep in mind that as soon as the player or the house busts, the round is over. Detect a bust after each dealt card by checking the busted property for the player or the house respectively. Hint: Use the break; keyword to escape a loop without escaping the method.
• After the loop ends, evaluate the winner by calling the houseWins method and use the incrementWinsAndLossesForHouseWins: to keep the tally of the rounds.
• Finally, use a pair of NSLog()s to print the descriptions of player and house to the console.

8. Navigate the FISAppDelegate.m file and import FISBlackjackGame.h. It's time to play some Blackjack! Inside the application:didFinishLaunchingWithOptions: method, create an instance of FISBlackjackGame called game. Call playBlackjack on game a few times. Run the scheme with ⌘ R and watch the results of the hands appear in the debug console!

2015-10-02 16:28:41.638 BlackJack[9979:383041] House wins!
2015-10-02 16:28:41.638 BlackJack[9979:383041] FISBlackjackPlayer:
  name: Player
  cards: ♦9 ♥8 ♣Q
  handscore  : 27
  ace in hand: 0
  stayed     : 0
  blackjack  : 0
  busted     : 1
  wins  : 0
  losses: 1
2015-10-02 16:28:41.639 BlackJack[9979:383041] FISBlackjackPlayer:
  name: House
  cards: ♥10 ♥6
  handscore  : 16
  ace in hand: 0
  stayed     : 0
  blackjack  : 0
  busted     : 0
  wins  : 1
  losses: 0
2015-10-02 16:28:41.639 BlackJack[9979:383041] Player wins!
2015-10-02 16:28:41.640 BlackJack[9979:383041] FISBlackjackPlayer:
  name: Player
  cards: ♠A ♣K
  handscore  : 21
  ace in hand: 1
  stayed     : 1
  blackjack  : 1
  busted     : 0
  wins  : 1
  losses: 1
2015-10-02 16:28:41.640 BlackJack[9979:383041] FISBlackjackPlayer:
  name: House
  cards: ♠5 ♦5 ♠4 ♦8
  handscore  : 22
  ace in hand: 0
  stayed     : 0
  blackjack  : 0
  busted     : 1
  wins  : 1
  losses: 1
2015-10-02 16:28:41.640 BlackJack[9979:383041] House wins!
2015-10-02 16:28:41.698 BlackJack[9979:383041] FISBlackjackPlayer:
  name: Player
  cards: ♣Q ♣5 ♠Q
  handscore  : 25
  ace in hand: 0
  stayed     : 0
  blackjack  : 0
  busted     : 1
  wins  : 1
  losses: 2
2015-10-02 16:28:41.699 BlackJack[9979:383041] FISBlackjackPlayer:
  name: House
  cards: ♥A ♣J
  handscore  : 21
  ace in hand: 1
  stayed     : 0
  blackjack  : 1
  busted     : 0
  wins  : 2
  losses: 1

Advanced

These are some options for continuing to work on this concept beyond the provided testing suite. You should checkout a new branch called advanced to avoid destroying your solution. These assignments may break the test successes that you've accomplished, so rely on behavioral testing via NSLog()s in the FISAppDelegate to check your code.

1. Refactor the dealCardToPlayer and dealCardToHouse methods into a single method that accepts a FISBlackjackPlayer argument and uses the same logic to deal to either player.

2. Refactor the processPlayerTurn and processHouseTurn methods into a single method that accepts a FISBlackjackPlayer argument and uses the same logic to offer a turn to both players.

3. Refactor the houseWins method to accommodate the possibility of a "push" (when both the House and the Player have blackjack hands). Can you accomplish this while returning a BOOL? (Hint: Probably not.) Should the method still be called houseWins after you've changed the way it works?

4. Add additional "seats" to the game, meaning, add additional FISBlackjackPlayer instances. Will you add them as properties, or convert the player property into an array of players? Remember that Blackjack is scored individually against the house, but all of the players are dealt from the same deck. If you've added players to the "table", do you need more cards in the deck? Casinos usually run blackjack games with triple (3) or sextuple (6) decks shuffled together. How can you alter the FISCardDeck class to accommodate this?

5. Add properties to the FISBlackjackPlayer class to save information about their current wallet and their current bet. Track the changes to this information when each round is evaluated (i.e. if the House wins, the House gets the bet).

6. Create a subclass of FISBlackjackPlayer called FISBlackjackShark. Override the shouldHit method from the parent class to evaluate the best move in accordance with a Blackjack strategy card.

• (Easy) Make a decision based upon whether the current hand score is soft (contains an Ace) or hard (without an Ace).
• (Hard) Make a decision based upon the cards currently in the House's hand. How can you transport this information from the instance of FISBlackjackGame to the instance of FISBlackjackShark? Should the shark try to get that information on its own, or should the game be responsible for handing this information to the shark every time the house takes a card?

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