General

Question 1

Where can you test Apple iPhone apps if you don’t have the device?

Answer 1

• iOS simulator can be used to test mobile applications
• xCode tool that comes along with iOS SDK includes Xcode IDE as well as the iOS Simulator
• Xcode also includes all required tools and frameworks for building iOS apps.
• However, it is strongly recommended to test the app on the real device before publishing it.

Question 2

Does iOS support multitasking?

Answer 2

iOS 4 and above supports multi-tasking and allow apps to remain in the background until they are launched again or until they are terminated

Question 3

Which JSON framework is supported by iOS?

Answer 3

SBJson framework is supported by iOS. It is an JSON parser and generator for Objective-C. SBJson provides flexible APIs and additional control that makes JSON handling easier.

Question 4

What are the tools required to develop iOS applications?

Answer 4

OS development requires Intel-based Macintosh computer and iOS SDK

Question 5

Name the framework that is used to construct application’s user interface for iOS?

Answer 5

The UIKit framework is used to develop application’s user interface for iOS. UIKit framework provides event handling, drawing model, windows, views and controls specifically designed for a touch screen interface.

Question 6

Name the application thread from where UIKit classes should be used?

Answer 6

UIKit classes should be used only from an applications’s main thread.

• Note: The derived classes of UIResponder and the classes which manipulate application’s user interface should be used from application’s main thread.

Question 7

Which API is used to write test scripts that help in exercising the application’s user interface elements?

Answer 7

UI Automation API is used to automate test procedures

Test scripts are written in JavaScript to the UI Automation API.

This in turn simulates user interaction with the application and returns log information to the host computer.

Question 8

Why an app on iOS device behaves differently when running in foreground than in background?

Answer 8

Application behaves differently when running in foreground than in background because of the limitation of resources on iOS devices.

Question 9

How can an operating system improve battery life while running an app?

Answer 9

• An app is notified whenever the operating system moves app between foreground and background.
• The operating system improves battery life while it bounds what your app can do in the background.
• This also improves the user experience with foreground app.

Question 10

Which framework delivers event to custom object when app is in foreground?

Answer 10

• The UIKit infrastructure takes care of delivering events to custom objects.
• As an app developer, you have to override methods in the appropriate objects to process those events.

Question 11

What is .plist

Answer 11

In iPhone development, Property Lists are a key value story that your application can use to save and retrieve data.

Question 12

What is IPA

Answer 12

IPA stands for iOS App Store Package, is an iPhone application archive file which stores an iPhone app.

Question 13

What is Xib

Answer 13

The .xib file extension is most commonly associated with interface builder files. Interface Builder is a graphics editing software that is used to design and test the user interfaces of a variety of software products.