In general, you do not need to access the run loop directly, though there are some (networking) components that may allow you to specify which run loop they will use for I/O processing
After doing so, it will then return to its loop, processing input from various sources, and "sleeping" if there is no work to do.
Top iOS Interview Questions And Answers for Beginners
iOS Interview Questions with Answers part4
What are the differences between Cocoa and Cocoa Touch?
Your apps will scale automatically on iPhone 6, iPhone 6 Plus screens.
What is .ipa in iOS ?
2.If an iPhone thrown upward ,how to measure the height device travelled ?
Put your phone on the table. What is it’s acceleration? That’s easy, right? It has an acceleration of zero m/s2 because it is stationary and STAYING stationary. Now give it a toss (but don’t really because you could totally break your phone). What’s it’s acceleration while it’s in the air and not touching your hand? Yes, it is in free fall and has an acceleration of 9.8 m/s2 towards the ground.
Now, if you know the acceleration and the time the object is in the air with this acceleration (since it is recorded from the phone) then you can find the height.
3.What are layer objects and what do they represent?
Layer objects are data objects which represent visual content. Layer objects are used by views to render their content. Custom layer objects can also be added to the interface to implement complex animations and other types of sophisticated visual effects.
iOS Interview Questions And Answers part12
Secrets to Effective iPhone App Marketing
iOS Interview Questions with Answers part2
Apple provides golden masters of iOS 8, Xcode 6 to developers before the Release of iOS 8
4.Apart from incorporating views and controls, what else an app can incorporate?
Apart from incorporating views and controls, an app can also incorporate Core Animation layers into its view and control hierarchies.
5.If you wish to define your custom view. Which class will be subclassed?
Custom views can be defined by subclassing UIView.
Views along with controls are used to provide visual representation of the app content. View is an object that draws content in a designated rectangular area and it responds to events within that area.
7.How do you change the content of your app in order to change the views displayed in the corresponding window?
To change the content of your app, you use a view controller to change the views displayed in the corresponding window. Remember, window itself is never replaced.
Some important points About View Controller.
What is MVC in iPhone?
How to make UIView with rounded corners?
Some important notes about View in iPhone.
8.What is the purpose of UIWindow object?
The presentation of one or more views on a screen is coordinated by UIWindow object.
9.Which is the super class of all view controller objects?
UIViewController class. The functionality for loading views, presenting them, rotating them in response to device rotations, and several other standard system behaviours are provided by UIViewController class.
10.Which object manage the presentation of app's content on the screen?
View controller objects takes care of the presentation of app's content on the screen. A view controller is used to manage a single view along with the collection of subviews. It makes its views visible by installing them in the app’s window.
iOS Interview Questions And Answers Part 8
iOS Interview Questions And Answers Part 7
Top 5 Frequently Asked iOS Interview Questions And Answers.
Confusion about delegate and protocol in Objective-C
Xcode cannot run using the selected device
11. Are document objects required for an application? What does they offer?
Document objects are not required but are very useful in grouping data that belongs in a single file or file package.
12.Which app specific objects store the app's content?
Data model objects are app specific objects and store app’s content. Apps can also use document objects to manage some or all of their data model objects.
13.What happens if UIApplication object does not handle an event?
In such case the event will be dispatched to your app delegate for processing.
14.How is the app delegate is declared by Xcode project templates?
App delegate is declared as a subclass of UIResponder by Xcode project templates.
What are required delegates and data sources for Table View?
What is the use of plist ?
iPhone Core Animation - Drawing a Circle
How to animate a view or image along a curved path.
15.Which object is create by UIApplicationMain function at app launch time?
The app delegate object is created by UIApplicationMain function at app launch time. The app delegate object's main job is to handle state transitions within the app.
16.What is the use of controller object UIApplication?
Controller object UIApplication is used without subclassing to manage the application event loop.
It coordinates other high-level app behaviours.
It works along with the app delegate object which contains app-level logic.
17.Who calls the main function of you app during the app launch cycle?
During app launching, the system creates a main thread for the app and calls the app’s main function on that main thread. The Xcode project's default main function hands over control to the UIKit framework, which takes care of initializing the app before it is run.
18.List down app's state transitions when it gets launched.
Before the launch of an app, it is said to be in not running state.
When an app is launched, it moves to the active or background state, after transitioning briefly through the inactive state.
19.Where can you test Apple iPhone apps if you don’t have the device?
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.
20.Difference between View and Layer?
-Represent position, shape and anchor point
-Do not receive touch events Light-weight
-Can receive touch eventsAre always backed by a Layer on iOS
-No implicit animations.
iOS Interview Questions with Answers part5
iOS Interview Questions with Answers part6
Basic iOS interview Questions And Answers
iOS Interview Questions with Answers part3
Top iOS Interview Questions And Answers for Beginners