Which of the following contains the INCORRECT definition of a Predefined Macro ?

What's the hierarchy of UIButton until NSObject ?

(...) are used by Cocoa and Cocoa Touch objects for a variety of different situations

If you start a class definition that conforms to a specified (...), you will not need to relist all the methods you will implement for that protocol in the @interface section.

A category is a group of related methods for a class, and all of the methods defined in a category are available through the class as if they were defined in the main interface file.

Which one is not a property of NSError class?

Can an exception caught in @catch be re-thrown?

What class specifiers are supported?

Output of the following code?

What is a SEL?

What is the id type?