Declaring, Properties, Synthesizing, and Implementing int[] array in Objective C

Question

How do you declare, set properties, synthesize, and implement an int array of size 5 in Objective C? I'm writing this code for an iphone app. Thanks.

Answer 1

You shouldn't use int in this case if you want to use an array. Use NSNumber and put those 5 NSNumbers into an NSMutableArray.

@interface testClass: NSObject {
     NSMutableArray* numbers;
}
@property (nonatomic, retain) NSMutableArray* numbers;
-(id)initWithValue:(NSNumber *)initialValue;
@end


@implementation testClass
@synthesize numbers;
-(id)initWithValue:(NSNumber *)initialValue {
     numbers = [[NSMutableArray alloc] initWithCapacity:5];
     [numbers addObject:initialValue];
     return self;
 }
@end

Is the code for the interface and implementation with synthesize(not tested BTW). What are you trying to accomplish?

Good quick intro

Answer 2

I think the "Cocoa-y" thing to do is hide the int array even if you use it internally. Something like:

@interface Lottery : NSObject {
    int numbers[5];
}

- (int)numberAtIndex:(int)index;
- (void)setNumber:(int)number atIndex:(int)index;
@end

@implementation Lottery

- (int)numberAtIndex:(int)index {
    if (index > 4)
     [[NSException exceptionWithName:NSRangeException reason:[NSString stringWithFormat:@"Index %d is out of range", index] userInfo:nil] raise];
    return numbers[index];
}

- (void)setNumber:(int)number atIndex:(int)index {
    if (index > 4)
     [[NSException exceptionWithName:NSRangeException reason:[NSString stringWithFormat:@"Index %d is out of range", index] userInfo:nil] raise];
    numbers[index] = number;
}

Answer 3

I have a class variable:

NSInteger myInt[5];

So that I could use the normal myInt[1]=0 syntax in my code, I created a property that returns an integer pointer:

@property (nonatomic, readonly) NSInteger *myInt;

Then created the following getter method:

-(NSInteger *) myInt {
  return myInt
}

Now I can use something like class.myInt[1]=0;

Well, I don't know for sure this works, but it seems to. I just thought I'd put this out there if someone else wants to try it.