How to extend my method that checking if 2 cards are matched to 3 cards that are matched?

Question

I'm following the Stanford course, and we had to build a method for the app that checks for 2 cards matching, this is how the model that have the logic looks like (the method to look there is flipCardAtIndex):

#import "CardMatchingGame.h"
#import "PlayingCardsDeck.h"

@interface CardMatchingGame()

@property (readwrite, nonatomic) int score;
@property (strong, nonatomic) NSMutableArray *cards;
@property (strong, nonatomic) NSString *notification;
@end        


@implementation CardMatchingGame


-(NSMutableArray *) cards {

    if (!_cards) _cards = [[NSMutableArray alloc] init];
    return _cards;
}


-(id)initWithCardCount:(NSUInteger)count usingDeck:(Deck *)deck {

    self = [super init];

    if (self) {

        for (int i = 0; i < count; i++) {
            Card *card = [deck drawRandonCard];

            if (!card) {
                self = nil;
            } else {
                self.cards[i] = card;
            }
        }
    }
    return self;
}


-(Card *) cardAtIndex:(NSUInteger)index {

    return (index < self.cards.count) ? self.cards[index] : nil;
}


#define FLIP_COST 1
#define MISMATCH_PENALTY 2
#define BONUS 4

-(void) flipCardAtIndex:(NSUInteger)index {

    Card *card = [self cardAtIndex:index];

    if (!card.isUnplayable) {

        if (!card.isFaceUp) {

            for (Card *otherCard in self.cards) {

                if (otherCard.isFaceUp && !otherCard.isUnplayable) {

                   int matchScore = [card match:@[otherCard]];

                    if (matchScore) {

                        otherCard.unplayble = YES;
                        card.unplayble = YES;

                        self.notification = [NSString stringWithFormat:@"%@ & %@  match!", card.contents, otherCard.contents];

                        self.score += matchScore * BONUS;
                    } else {
                        otherCard.faceUp = NO;
                        self.score -= MISMATCH_PENALTY;
                        self.notification = [NSString stringWithFormat:@"%@ did not matched to %@", card.contents, otherCard.contents];
                    }
                    break;
                }

            }
            self.score -= FLIP_COST;
        }
        card.faceUp = !card.isFaceUp;
    }
}


@end

And this is the class model of the whole game, that got the actual matching method:

#import "PlayingCards.h"


@implementation PlayingCards

@synthesize suit = _suit;

//overriding the :match method of cards to give different acore if its only a suit match or a number match
-(int)match:(NSArray *)cardToMatch {

    int score = 0;

    if (cardToMatch.count == 1) {
        PlayingCards *aCard = [cardToMatch lastObject];

        if ([aCard.suit isEqualToString: self.suit]) {
            score = 1;
        } else if (aCard.rank == self.rank) {
            score = 4;
        }

    }

    return score;

}
//more stuff...

W already created it with an array so we will be able to extend it for more objects, but now i'm trying to figure out how do I extend it :/

This is my github for the project https://github.com/NirOhayon/Matchismo

i'm new to objective C and would appreciate it munch if you could help me to figure it out.

Thanks a bunch

Answer 1

You can chain these with a loop to check them all. Very basic way of doing it. Just loop through each card and check it against the "self" card that you have and increment the score instead of setting it.

-(int)match:(NSArray *)cardToMatch {

    int score = 0;

    for(int i = 0; i < cardToMatch.count; i++) {
        PlayingCards *aCard = cardToMatch[i];
        if ([aCard.suit isEqualToString: self.suit]) {
            score += 1;
        } else if (aCard.rank == self.rank) {
            score += 4;
        }
    }

    return score;

}

For flipCardAtIndex: , I would change it to flipCardsAtIndexes:(NSArray*)indexes, where indexes is an NSArray of NSNumbers. Then I would run a for loop checking and removing any cards that are unplayable or faceup, and pass through the remaining cards at those indexes to check match, and retrieve the match score.

To tell your view controller to add another card depends on how you have your view controller set up. You could do a protocol in a method that your view controller becomes the delegate of, and through a protocol method, tell it to switch. It could also be simpler than that, depending on how it checks your model of cards to decide what to show, if it sees three cards available instead of two, it could switch.

As the point of this exercise is to learn iOS programming, I want to give you a good head start and you should tweak and figure some stuff out on your own. I have a feeling you're a novice at programming, and if you are, you'll be surprised how much programming at your stage is trial and error. Eventually it will become second nature.