Question

Does it make sense to write self = [super init]; in a custom initialisation method while subclassing NSObject? I know it’s necessary when subclassing any other class, because it might have a custom initialisation, but does the NSObject init method do anything?

Answer 1

An object isn’t ready to be used until it has been initialized. The init method defined in the NSObject class does no initialization; it simply returns self.

So basically you don’t necessarily have to call [super init] in an NSObject subclass, but I still would recommend it. It’s simply a better design. If you change the superclass it will still work.

Source: NSObject Class Reference.