Question

This is my first post, so be kind 🙂

I’ve looked around for solutions but can’t seem to find one. Problem may be asking the question in a way that google will return useful results.

So, I have an NSMutableArray (called boardColCoords), and I have CGPoint (called touchLocation). I want to compare the two so that I can snap a UIImageView location to the proper coordinate in the boardColCoords array.

Here’s the relevant code:

UITouch *touch = [[event allTouches] anyObject];
CGPoint touchLocation = [touch locationInView:self.view];

NSNumber *boardSquareX = [boardColCoords objectAtIndex:i];

if (touchLocation.x - boardSquareX <= 12)
{
}

I know that 12 will eventually have to be changed, but I just want to get the subtraction working first. The specific error I get is:

Invalid operands to binary expression (‘CGFloat’ (aka ‘float’) and “NSNumber *).

Answer 1

NSNumber is a wrapper, you have to “extract” it’s value with something like floatValue to compare like that:

if (touchLocation.x - [boardSquareX floatValue] <= 12)