Question

What is the highest int that NSNumber allows? I’ve seen the answer elsewhere on these forums hence why I’m deeply confused here.

int miles = 35000;
vehicle.mileage = [NSNumber numberWithInt:miles];
NSLog(@"int value = %d", miles);
NSLog(@"mileage = %@", vehicle.mileage);

The output is:

int value = 35000
mileage = -30536

I must be missing some terrible easy here, but can someone explain to me why this is not working correctly?

UPDATE:
After looking further, vehicle.mileage is getting set correctly to 35000 but when I display this via NSLog(@”%@”, vehicle.mileage) it is outputting it incorrectly. I have yet to find the “magic” value when this stops working because as of now, it works for values up to ~30,000.

Answer 1

NSNumber is just a wrapper so it goes in overflow when the wrapped primitive type goes in overflow.
So if you use numberWithInt the maximum number allowed is INT_MAX (defined in limits.h), if you use a numberWithFloat the maximum number allowed is FLOAT_MAX, and so on.
So in this case you aren’t going in overflow, I doubt that INT_MAX would be so low.