Could [NSMutableArray array] return nil?

Question

For example in low memory conditions. I'm reading third party code and I saw this

NSMutableArray *array = [NSMutableArray array];

if (array != nil) {

    [array addObject:anObject];
}

I've never check this after creating an array that way nor alloc+init but now I'm in doubt.

Answer 1

Technically, it could return nil.

The probability of such a failure at that point is incredibly unlikely. Your app would probably crash or abort before a nil were returned. Consider it about as unlikely as malloc returning NULL.

My implementations have used checked object creation for years - I cannot remember ever seeing [NSMutableArray array] return nil in that time in development/testing.

Note that this answer is specific to [NSMutableArray array], not any/every initializer/constructor in existence. [NSMutableArray array] is nearly the most 'consistent' class of initializer/constructor in this regard because there is no reason for it to fail under normal circumstances.

Answer 2

Yes. An object instantiation that fails for any reason should return nil unless the method states otherwise.