Swift Interview Questions

Listed below are some of topics to be familiar before attending an iOS//Swift interviews. These are very trivial questions but in future this space will updated with more scenario based questions

• What are the different app states?
• What is JSON?
• What do you mean by REST?
• Difference between class and struct?
• What are Optionals?
• Difference between Optional Chaining and Optional Binding?
• why do we have to use UICollectionViewFlowLayout?
• Difference between frame and bounds?
• What is NSCoder class used for? 
• What is NSOperationQueue and when should we use it?
• What are extensions? Explain the difference between extension and subclassing?
• Difference between delegates and NSNotifications?
• What are protocols in Swift?
• What is interpolation?
• Explain type inference in Swift?
• Difference between Auto Layout and Adaptive Layout?
• Is possible to use an Objective-C framework in Swift? 
• Explain the different life cycle of UIViewController?
• Difference between xib’s and Storyboards.
• Explain MVC?
• What is MVVM?
• what is an app bundle?
• Write a sample code for Singleton design pattern?
• What is difference between Unit tests and UI Test in Xcode?
• Can you make updates to UI from a background thread? 
• Difference between let and var keywords in Swift?
• What are generics? Can you write generics example code?
• Difference between designated and convenience initialiser?