Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the (...) programming language. This is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch.

While calling a function by reference, it will copy the actual value of an argument into the formal parameter of the function. In this case, changes made to the parameter inside the function have no effect on the argument. Is the statement above True ?

Which method creates and returns an NSNumber object containing a given value, treating it as an NSInteger.

Which one is the base class of all objects in Objective-c ?

The description above is essentially related to which feature of Objective-C programming language ?

Objective-C allows you to define protocols, which declare the methods expected to be used for a particular situation.

A UIView is a superclass of:

Which of these methods is NOT invoked by the runtime itself?

How is a selector typically represented in memory?

What's the difference between nil and NULL?

What are @try and @catch?