iOS Development with Swift 2 Interview Questions & Answers

Question 1. What Is Xcode?

Answer :

Xcode is Apple’s integrated development environment (IDE) that you use to design apps for Apple products. It provides various tools to manage your entire development workflow from creating your app, to testing, submitting and optimizing it to the App store.

Question 2. How Multiple Line Comments Can Be Written In Swift?

Answer :

Multiple line comments can be written as forward-slash followed by an asterisk (/*) and end with an asterisk followed by a forward slash (*/).

Question 3. What Are The Collection Types Available In Swift?

Answer :

Multiple line comments can be written as forward-slash followed by an asterisk (/*) and end with an asterisk followed by a forward slash (*/).

Question 4. What Are The Control Transfer Statements Used In Swift?

Answer :

Control transfer statements used in Swift include −

• Break
• Continue
• Fallthrough
• Return

Question 5. What Is The Characteristics Of Switch In Swift?

Answer :

It supports any kind of data and not only Synchronizes it, but also checks for equality. The Switch statement must be exhaustive, which means that you have to cover all possible values for your variable.

Question 6. What Is The Question Mark (?) In Swift?

Answer :

The question mark (?) is used during the declaration of a property. It tells the compiler that this property is optional and whether the property may hold a value or not.

Question 7. What Is The Use Of Double Question Marks (??)?

Answer :

To provide a default value for a variable.

Question 8. What Is The Difference Between Let And Var In Swift?

Answer :

The let keyword is used to declare constants, while var is used for declaring variables.

Question 9. What Is A Guard Statement In Swift?

Answer :

The guard statement evaluates a Boolean condition and proceeds with program execution if the evaluation is true.

Question 10. What Is Gcd? How Is It Used?

Answer :

GCD is the most commonly used API to manage concurrent code and execute operations asynchronously at the UNIX level of the system. GCD provides and manages queues of tasks.

Question 11. What Is Synchronous Vs. Asynchronous In Gcd?

Answer :

A synchronous function returns only after the completion of a task that it orders.

An asynchronous function, on the other hand, returns immediately, ordering the task to be done, but not waiting for it.

Question 12. What Is Mvc?

Answer :

MVC is a design pattern that stands for Model View Controller. This design pattern separates the data from its display, mediated by a View Controller.

Question 13. What Are Delegates?

Answer :

Delegates are a design pattern. A delegate is just an object that another object sends messages to when certain things happen.

Question 14. What Is Core Data?

Answer :

Core Data is an object graph manager, which also has the ability to persist object graphs to a persistent store, on a disk.

Question 15. What Is The Purpose Of The Reuseidentifier?

Answer :

Reusability of an already allocated object.