1. Explain me what is Swift?

Swift is a programming language for development of applications for OS X, iOS, watchOS, and tvOS. These applications are developed using C and Objective-C. It does not have the constraints of C Programming. It has features for easier development and provides more flexibility.

2. Explain xib?

.xib is a file extension that is associated with Interface Builder files. It is a graphics software that is used to test, develop and design the User Interfaces of different software products. Such extension files also contains development time format files that includes interface files created with the interface builder softwares.

3. Explain me what is Fast Enumeration?

Fast enumeration is a iOS Programming Language feature that enables you to enumerate over the contents of a collection. It will also make your code execute your code faster due to internal implementation which gets reduced message sending overheads and increased pipelining potential.

4. What is difference between "protocol" and "delegate"?

protocol is used the declare a set of methods that a class that "adopts" (declares that it will use this protocol) will implement.
Delegates are a use of the language feature of protocols. The delegation design pattern is a way of designing your code to use protocols where necessary.

5. Explain the difference between Inheritance and Category?

Category enables to add methods only. It does not allow the inclusion of Data Members unlike Inheritance where both the Data and Methods can be added. Category includes Complete Application in its Scope whereas Inheritance's scope is only within that particular File.

6. Explain what is a Class?

The entire set of data of an object can be made a user-defined data type using a class. Objects are basically variables of Class type. Once a Class has been defined, it is possible to create multiple Objects of its type. A Class is a collection of Objects of similar type.

7. What is IPA?

IPA represents iOS App Store Package. It has an .ipa extension which represents iPhone application archive file that stores an iPhone application. Every file is compressed with a Binary for the ARM architecture and can only be installed on an iPhone, ipad or an iPod Touch. It is mostly encrypted with Apple's FairPlay DRM Technology.

8. What is autorealease pool?

Every time -autorelease is sent to an object, it is added to the inner-most autorelease pool. When the pool is drained, it simply sends -release to all the objects in the pool.
Autorelease pools are simply a convenience that allows you to defer sending -release until "later". That "later" can happen in several places, but the most common in Cocoa GUI apps is at the end of the current run loop cycle.

9. What is Cocoa?

Cocoa is an Application Development Environment for Mac OS X Operating System and iOS. It includes Compilations of a Runtime System, Object-Oriented Software Libraries and an Integrated Development Environment.

10. Explain Web Services?

The Web Services are the Application Components which enables communication using Open Protocols. These Web Services are Self – Describing and Self – Contained. Web Services can be found out by using UDDI. The base for development of Web Services functionality is Extensible Markup Language (XML).

Download Interview PDF