Swift Interview Questions and Answers in 2023

If you want to work as a successful Swift developer for a top Silicon Valley firm or build a team of talented Swift developers, you've come to the right spot. We've carefully compiled a list of Swift developer interview questions for your Swift interview to give you an idea of the kind of Swift interview questions you can ask or be asked.

Last updated on Mar 21, 2023

Swift is a compiled and innovative programming language created by Apple Inc in June 2014 for creating mobile and desktop apps. This programming language is compatible with watchOS, macOS, iOS, and tvOS.

The Swift programming language was built by Apple to interact with both Cocoa Touch and Cocoa. Swift is compatible with a variety of operating systems, including FreeBSD, Linux, Darwin, and others. This language was created to work in conjunction with Apple's Objective-C library and Cocoa framework.

Whether you are a candidate actively looking for Swift interview preparation or a recruiter looking for Swift developers, the following list of Swift interview questions will be of great use for you.

Swift interview questions and answers


Distinguish Objective C from Swift.

This is a common Swift interview question.

  • Swift is a class-based object-oriented programming language, whereas Objective-C is an object-oriented and functional programming language.
  • Swift allows you to use dynamic libraries, but Objective-C does not.
  • Tuples are supported by Swift, although they are not supported by Objective-C.
  • In Swift, semicolons are optional, whereas they are needed in Objective-C.
  • Swift is an open-source programming language, whereas Objective-C is a proprietary Apple language that is not open-source.
  • In Objective C, we must declare the variable as "NSString" and the constant as "int," whereas in Objective C, we must declare the variable as "NSString" and the constant as "int."
  • Objective C does not allow us to define methods in structure, classes, or enumeration, whereas Swift does.


Is there a way to test the iPhone apps without an iPhone?

This is a trick question. If we do not have an iOS device, we can test our application on the Mac system using Apple's simulators.


Name some programs that are required in the development of iOS applications?

This is a common Swift interview question for experienced 2022.

  • Mac/MacMini: We must obtain a Mac with an Intel-based processor that runs Mac OS. Don't worry, if we have our own PC, we can still develop iOS apps using the Mac Mini.
  • Xcode: Xcode is the Apple IDE (Integrated Development Environment) for both iOS and Mac OS apps. It includes a visual layout editor as well as a code editor for dealing with the logic, user interface, and response behind the scenes.
  • Swift Programming Language: The logic in the code editor will be written in Swift, an Apple-created programming language.
  • Apple Developer Program: Through this program, the developer is able to publish our app on the App Store.


Mention some characteristics of Swift.

This is a popular Swift interview question. The interviewer doesn't want you to turn into a storyteller here. All they want to know is how strong are your basics. You can start with the following points and they will know that you have a strong base.

  • structs and enums that are more impressive
  • Protocol-focused
  • Types that are optional
  • Type Semicolons are not required in safety and type inference language
  • Initializers that are required
  • By default, it is safe


What is PLIST?

PLIST is an abbreviation for Property List. PLIST is a dictionary of values and keys that can be saved in our file system using the.plist file extension. The property list is used to store fewer data in a portable and lightweight manner. Typically, they are written in XML.

The following are examples of different types of property lists:

  • List of Binary Properties
  • List of XML Properties
  • List of ASCII Legacy Properties


What is a protocol?

The protocol is a very common feature of the Swift programming language, and it is a concept similar to a java interface. A protocol is a blueprint of properties, methods, and other criteria that are appropriate for a specific task.

The protocol, in its most basic form, is an interface that describes some methods and properties. Instead of implementation, the protocol is simply described as a skeleton of properties or methods. Enumerations, functions, and classes can be used to implement properties and methods.


What is core data?

Core data is one of Apple's most powerful database frameworks for macOS and iOS apps. In our applications, core data is used to manage the model layer object. We can think of Core Data as a framework for filtering, modifying, saving, and tracking data within iOS apps. We can easily map the objects in our app to the table records in the database using core data without knowing any SQL. The M in the MVC structure stands for core data.


What is a base class?

In Swift, any class that doesn't inherit from any other class is known as a base class. Classes in a Swift programming language are not inherited from the universal base class. The developer defines the classes without specifying the superclass, and it becomes the base class automatically.


What is optional chaining?

Optional chaining is a handy mechanism that we may utilize in conjunction with the option to call the methods, properties, and subscripts on the options, which can be nil or not. We may try to obtain a value from a chain of optional values during this operation.

  • Calling the subscript, method, or property of an optional will return a value if the optional has a value.
  • If optional is nil, the subscript, method, and property will all return nil when called.


What is MVC?

The model view controller is abbreviated as MVC. The MVC pattern is a powerful software architectural paradigm for creating apps. MVC is based on the fundamentals of Object-Oriented Programming. It organizes the data and interaction flow in our app. In iOS development, Model-View-Controller is a crucial foundational notion to grasp. The MVC pattern is used by many iOS frameworks, including UIKit and Cocoa Touch, for communications and structured data flow.

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Wrapping up

The above list of Swift interview questions will be an important part of your Swift interview preparation. These Swift interview questions will assist you in solving similar queries or generating new ones. A Swift interview, on the other hand, would not consist solely of these technical Swift interview questions. A Swift interview may also include questions regarding a person's social and life abilities. This allows the recruiter to determine whether the individual can persevere in difficult situations while also assisting their coworkers. As a recruiter, finding someone who gets along with the rest of the team is critical.

You can work with Turing if you're a recruiter looking to hire from the top 1% of Swift developers. If you're an experienced swift developer searching for a new opportunity, Turing.com is a great place to start.

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