1.Define Visibility in Objective C? Answer:- Visibility :
The Objective C has variable by default @protected. But methods are not used with access specifier they are public by default. To hide any method from out side . Declare and Implement it in .m file using category .
NSCoder is an abstractClass which represents a stream of data. They are used in Archiving and Un-archiving objects. NSCoder objects are usually used in a method that is being implemented so that the class conforms to the protocol.
1.What is the difference Between APPKit and UIKit?
AppKit is included in the OS X SDK only.It provides all the classes and controls you need for creating Mac applications.Most of these classes share a common naming prefix starts with NS and classes you will be working with include NSWindow, NSButton, NSTableView.
1.Difference b/w #define and #pragma and #import? Answer:
There are different ways to create constants in Objective-C, but the easiest way is to use #define statements.#define however is a preprocessor that replaces all instance with it even before compilation starts.
1.NSBundle Main bundle? Answer:-
It is used to pick the data from resources.
2.What is UI application? Answer:-
Every iPhone has UI application.it is the starting point of the every application.It is responsible for initializing and display your application on UI Window and also responsible for loading your application.