(...) is an abstractClass which represents a stream of data. They are used in Archiving and Unarchiving objects. (...) objects are usually used in a method that is being implemented so that the class conforms to the protocol.

The (...) method can be used to see if an object belongs to a class that implements a particular protocol.

In Objective-C, retain counts are the way in which memory is managed in Objective-C

A derived class can access all the private members of its base class if it's defined in the interface class

Which one is correct (legal) floating-point literal ?

What happens when the following code executes?

A class can have two methods with the same name, but with different argument types.

Why should you use an autorelease pool ?

Which of the following statements is correct?

What сan you use to avoid msgSend function overhead?

What happens if two categories define methods with the same names for the same class?