Checking if an array contains a certain object (iOS)

Question

I need to check if a certain array contains a certain object, and if it does, delete that object. If it hasn't got that object, the funciton is suposed to add it into the array. The problem is that the object is always added because the checking statement always return false.

Here's my current function:

- (void) myFunction:(NSString *)parameter {

    if (![myMutableArray containsObject:parameter]) {

        [myMutableArray addObject:parameter];
        NSLog(@"%@ added", parameter);

    } else {

        [myMutableArray removeObject:parameter];
        NSLog(@"%@ deleted", parameter);

    }
}

Answer 1

containsObject is calling isEqual on each of the object in the arrays. What type of object are you checking for? If it's a custom object, override and implement the method isEqual.

I'm guessing you're trying to check the value of the object, but containsObject is actually calling isEqual which is comparing the reference to the object, and not its actual value.