Question

I want to implement thing like that but i get error in add because of id !!!

NSMutableArray *rgbarray = [[NSMutableArray alloc] init];
 NSInteger rgb[3];
            const CGFloat *components = CGColorGetComponents(cgcolor);
            CGFloat cgred = components[0];
            CGFloat cggreen = components[1];
            CGFloat cgblue = components[2];
            rgb[0] = cgred;
            rgb[1] = cggreen;
            rgb[2] = cgblue;

            [rgbarray addObject:rgb];

i want to add rgb instead of id ?

Answer 1

You can only add pointers to instances of objects into NSMutableArray

You can use a NSDictionary or create your own subclass of NSObject to wrap the 3 values.

NSDictionary * rgbDictionary = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithFloat:cgred], @"cgred", [NSNumber numberWithFloat:cggreen], @"cggreen", [NSNumber numberWithFloat:cgblue], @"cgblue", nil];

[rgbarray addObject:rgbDictionary];

To retrieve the values

NSDictionary * rgbDictionary = [rgbArray objectAtIndex:0];
CGFloat cgred = [[rgbDictionary objectForKey:@"cgred"] floatValue];
CGFloat cggreen = [[rgbDictionary objectForKey:@"cggreen"] floatValue];
CGFloat cgblue = [[rgbDictionary objectForKey:@"cgblue"] floatValue];

I would actually use the subclass approach. Since you were trying to code with a C array for your values, the NSDictionary approach will get you past the error.