Question

I have an instance of NSNumber * did inside a class called Reservation.
Below myres is an instance of Reservation

myres.did = [[NSNumber alloc] initWithInt:[[[data objectForKey:@"discount"] did] intValue]];

When I do this everything works just fine. However the code is ugly, and when I do:

myres.did = [data objectForKey:@"discount"] did];

My code breaks down.. I know that [[data objectForKey:@"discount"] did] returns an object, which is an NSNumber.

Can some explain to me why is this? and what do I need to change in my code if I want to assign a NSNumber with another NSNumber?

Answer 1

Please see this supplemental answer which gives background to the copying of NSNumber.