How to create a 2D NSArray or NSMutableArray in objective C?

Question

I want to ask about the objective C question. I want to create a 2D NSArray or NSMutableArray in objective C. What should I do? The object stored in the array is NSString *. Thank you very mcuh.

Answer 1

This is certainly possible, but i think it's worthy to note that NSArrays can only hold objects, not primitive types.

The way to get around this is to use the primitive wrapper type NSNumber.

NSMutableArray *outer = [[NSMutableArray alloc] init];

NSMutableArray *inner = [[NSMutableArray alloc] init];
[inner addObject:[NSNumber numberWithInt:someInt]];
[outer addObject:inner];
[inner release];

//do something with outer here...
//clean up
[outer release];

Answer 2

Try NSMutableDictionary with NSNumbers as keys and arrays as objects. One dimension will be the keys, the other one will be the objects.

To create the specific "2D array"

NSMutableDictionary *twoDArray = [NSMutableDictionary dictionary];
for (int i = 0; i < 10; i++){
    [twoDArray setObject:arrayOfStrings forKey:[NSNumber numberWithInt:i]];
}

To pull the data

NSString *string = [[twoDArray objectForKey:[NSNumber numberWithInt:3]] objectAtIndex:5];
//will pull string from row 3 column 5 -> as an example