containsObject - why doesen't this work?

Question

Hi.

I have an array that I am trying to check wether or not an indexPath(.row) exists in.

I use this code:

if ([array containsObject:[NSNumber numberWithInt:indexPath.row]]){
    NSLog(@"Yep, it exists in there.");
}

the array consist of the numbers 3, 8 and 2. The index path loads numbers fromm 0 to 8 in a loop.

Can anybody see why this doesen't work?

Answer 1

containsObject: uses isEqual:, but NSNumber's equality comparison method is isEqualToNumber: Your code is inadvertently using the inherited isEqual which is just comparing pointers.

I think you'll have to iterate over array yourself and use isEqualToNumber:

Answer 2

The array had strings in it, not numbers :)

Thank you, Jim.

Answer 3

Since the array contains strings, you should compare against strings. To create a numeric string, use -stringWithFormat:. So:

if ([array containsObject:[NSString stringWithFormat:@"%d", indexPath.row]]){
    NSLog(@"Yep, it exists in there.");
}

A better solution is to store NSNumber's in the array.