usage of isMemberOfClass; returning false

Question

In the code below I thought the second condition would be true, but it is turning out as false. Am I missing something? Please help me understand.

NSArray *a         


        

Answer 1

You should be using isKindOfClass. Refer this for the difference.

Answer 2

This is the correct behavior. Try inspecting the actual class for that object:

NSArray *array = [[NSArray alloc] init];
NSLog(@"%@", NSStringFromClass([array class]));

The output you get is something like:

2013-02-15 23:42:31.272 Project[91998:c07] __NSArrayI

So the actual class is __NSArrayI (a private subclass of NSArray), not NSArray itself. Typically, isKindOfClass: provides more useful results.

Answer 3

NSArray is a class cluster. When you create an object of NSArray, internally it creates the object from its cluster. It adds simplicity to avoid creation of different type of objects depending upon the requirements.

For such cases you should use the function isKindOfClass. It checks the completer hierarchy to identify the kind of object.