Object only available in if statement in Obj - C? - ios

Question

probably an easy question...I'm a beginner programmer, so bear with me :)
I've made my first 'real' iPhone app that draws cards from a deck until a Joker is drawn, then the game is over.
So far, so good and it all works, except I have to use a work-around which I really hate.
My Deck object is only available where I declare it, which seems normal but yet irritating.
Basically, I have to make an entire new deck every time the user hits the "Draw Card" button...
- (IBAction)drawCard:(id)sender {
Deck *deck = [[Deck alloc]init];
deck.generate;
unsigned int randomIndex = arc4random_uniform(deck.deckArray.count);
Card *topCard = [deck.deckArray objectAtIndex:randomIndex - 1];
if (topCard.value == 11) {
NSString *cardInfo = [NSString stringWithFormat:#"You drew a Jack of %#", topCard.suit];
self.cardDrawn.text = cardInfo;
}else if (topCard.value == 12) {
NSString *cardInfo = [NSString stringWithFormat:#"You drew a Queen of %#", topCard.suit];
self.cardDrawn.text = cardInfo;
}else if (topCard.value == 13) {
NSString *cardInfo = [NSString stringWithFormat:#"You drew a King of %#", topCard.suit];
self.cardDrawn.text = cardInfo;
}else {
NSString *cardInfo = [NSString stringWithFormat:#"You drew a %d of %#", topCard.value, topCard.suit];
self.cardDrawn.text = cardInfo;
}
[deck removeCard];
if (topCard.value == 14) {
self.cardDrawn.text = #"You drew the Joker Bomb!";
//Destroy deck
deck = nil;
[drawCard setEnabled:NO];
[playAgain setEnabled:YES];
[playAgain setHidden:NO];
}
}
- (IBAction)playAgain:(id)sender {
self.cardDrawn.text = nil;
[drawCard setEnabled:YES];
[playAgain setEnabled:NO];
[playAgain setHidden:YES];
}
- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self =[super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
Deck *deck = [[Deck alloc]init];
deck.generate;
}
return self;
}
#end
If I take away Deck *deck = [[Deck alloc]init]; in my drawCard button method, I get a bunch of errors and the app won't build. I've tried #synthesizeing the deck object, but that doesn't seem to work either, and I also tried making a pointer to deck but that was kind of useless and did not work as well.
I wanted to implement a label that would show how many cards are left in the deck, but that would be impossible since a new deck is being generated every time the user taps drawCard.
Sorry if this is a stupid question & thanks!

Answer 1

#interface ViewControllerTheOPDidntProvideANameFor ()
#property (nonatomic, strong) Deck *deck;
#end
#implementation ViewControllerTheOPDidntProvideANameFor
- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
self =[super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
self.deck = [[Deck alloc]init];
[self.deck generate];
return self;
}
#end

Answer 2

There are some problems in your code. First of all what does "deck.generate;" do? That's not a valid Objective-C syntax.
The other thing is that you're realocating a deck everytime the drawCard method is called. Instead of using:
Deck *deck = [[Deck alloc]init];
You could declare Deck as an instance variable inside your interface and change the line above with:
deck = [Deck new];

Answer 3

In your .h file, declare something like this:
#property (nonatomic, strong) Deck *deck;
Then, in your .m file, initialize the deck (most likely in viewDidLoad or viewWillAppear) using something like this:
self.deck = [[Deck alloc] init];
Then, you'll be able to use the same deck property using self.deck like this:
[self.deck generate]; //Good practice to use brackets instead of dot notation for function calls in Objective-C since dot operators indicate properties
Hope this helps!
EDIT:
Per DarkDust's remark, you can use an instance variable as well:
//.h
#interface YourViewControllerName : UIViewController {
Deck *deck;
}
//.m
- (void)viewDidLoad
{
[super viewDidLoad];
//Initialize the deck
deck = [[Deck alloc] init];
}
Your deck will then be accessible using deck.