Swift iOS interview questions and answers

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The Guide is for YOU if
  • You are preparing for an iOS interview and want to improve your skills and knowledge and looking to level up your interview game and land your dream job.
  • You want to gain confidence and ease during iOS interviews by learning expert tips and curated strategies.
  • You want access to a comprehensive list of iOS interview QA to practice and prepare.

Swift is a very powerful language and it combines both object-oriented and functional programming. It has many exciting features such as closures, function pointers, tuples, and multiple return values, generics, functional programming patterns, etc. In this article, I have collected the most asked Swift iOS interview questions and provided the simplest answers possible. As an iOS developer, it’s essential to have a strong understanding of the core concepts that underlie the platform. Whether you’re interviewing for a new job or just looking to brush up on your skills, these five areas are sure to come up in any iOS-related conversation: language features, UI, threading and concurrency, memory management, and architecture and design patterns. In this blog post, we’ll take a closer look at each of these concepts and provide some example questions to help you prepare for your next iOS interview.

I have arranged the questions by five major concepts. In future, I will add difficulty level(Beginner, Intermediate and Advanced) (Worth reading Acing iOS Interview with Confidence)

  • Language features
  • UI – Auto layout & UIKit
  • Threading & concurrency
  • Memory management
  • Architecture and design pattern

Part – 1 Language features

Swift is the primary programming language used for iOS development, and it’s important to understand its syntax, semantics, and features. The questions are related to Swift language features such as control flow, access modifier, type safety, struct, generics, tuples etc. As a junior iOS developer, mastering the language features of Swift is crucial to your success in this field. This is why “Swift IOS Interview Questions and Answers – Language Features” is a vital resource for anyone looking to develop their skills and grow their career in iOS development. Here are a few example questions that you can expect:

  • What is the difference between a variable and a constant in Swift?
  • How do you define a function in Swift?
  • Can you explain the difference between a struct and a class in Swift?

Swift iOS interview questions and answers – Part 1

Part – 2 Auto layout & UIKit

The UI (user interface) of an iOS app is crucial to its success, and it’s important to have a strong understanding of the tools and frameworks used to create it. The questions are related to UI – Auto layout & UIKit such as frame, bound, autolayout constraints, xib, storyborad, safe area etc. Here are a few example questions:

  • What is Auto Layout and how does it work?
  • What is the difference between a UIView and a UIViewController in UIKit?
  • How do you create a custom view in iOS?

Swift iOS interview questions and answers – Part 2

Part – 3 Threading & concurrency

iOS apps are often built with multiple threads and it’s important to understand how to manage them. It will cover concurrency and thread-related topics such as GCD, NSOperation, operation queue, lock, semaphore, etc. Here are a few examples questions:

  • What is threading and why is it important in iOS development?
  • How do you use GCD (Grand Central Dispatch) in iOS?
  • What is the difference between a synchronous and an asynchronous task in iOS?

Swift iOS interview questions and answers – Part 3

Part – 4 Memory management

Understanding how iOS manages memory is crucial to developing efficient and stable apps. It will cover some core concepts of memory management such as ARC, retain cycle, circular dependency, reference cycle, capture list, and capture of self, etc. Here are a few example questions that can be expected:

  • What is reference counting and how does it work in iOS?
  • What is a strong reference and a weak reference in iOS?
  • How do you handle memory leaks in iOS?

Swift iOS interview questions and answers – Part 4

Part – 5 Architecture and design pattern

Architecture and Design Patterns: Having a strong understanding of the architecture and design patterns used in iOS development is key to creating maintainable and scalable apps. It will cover the different concepts of design and architectural patterns briefly such as MVC, MVVM, VIP, VIPER, structural, behavioral and creational design patterns in iOS etc. Here are a few example questions:

  • What is the Model-View-Controller (MVC) pattern and how is it used in iOS development?
  • What is the difference between a delegate and a data source in iOS?
  • Can you explain the Singleton pattern and when it should be used in iOS development?

Swift iOS interview questions and answers – Part 5

Worth reading Cracking the Behavioral Interview

Swift iOS interview questions and answers

Fellow iOS Developers, Please Keep In Mind

  • It’s important to keep in mind a few key points as you prepare for your interview. Firstly, it’s worth noting that there are over 1000 interview questions available in the interview section for you to review and prepare for. While reading the question, take the time to carefully consider your answer and think about the information that you want to convey. The answer provided here in this blog can be explained in a different way. You should also prepare your examples.
  • It’s also important to remember that these interview questions are not meant to be difficult. The interviewer is not looking to challenge you, but rather to start a conversation that will allow your abilities and interests to come to the forefront. They want to get to know you and your experience better.
  • Finally, it’s crucial to avoid simply answering questions with a “yes” or “no.” Interviewers are looking for more in-depth responses that include basic understanding, reasoning, explanation, and examples. So, make an effort to elaborate on your answers and provide specific, relevant information to support your response. This will demonstrate your thoughtfulness and show the interviewer that you are well-prepared for the interview.

For SwiftUI Interview Questions, Have a look at those articles –

SwiftUI is a modern, declarative framework for building user interfaces on Apple platforms. Its intuitive syntax and straightforward approach to layout make it a popular choice for iOS developers.

As a result, SwiftUI is often a topic of discussion in job interviews for iOS developers. In this blog post, we’ll be covering some of the most common SwiftUI interview questions and providing tips and resources for preparing for these types of questions. Whether you’re an experienced developer looking to brush up on your SwiftUI skills or a beginner preparing for your first iOS job interview, this post will provide valuable insights and resources to help you succeed. We’ll start by covering the basics of SwiftUI, including views, layout, and data binding. From there, we’ll delve into more advanced topics such as animations, custom views, and integrating with UIKit.

SwiftUI Interview Questions & Answers

SwiftUI Interview Questions and Answers – Part 1 – UI Basics

SwiftUI Interview Questions And Answers – Part 2 – UI Advance

SwiftUI Interview Questions And Answers – Part 3 – Data


While the basic technical questions are important, many interviewers also like to ask more open-ended and creative questions to gauge your problem-solving skills, your design sense, and your overall knowledge of the iOS ecosystem.

iOS Developer – Bonus Interview Questions

Planning to apply for iOS job? Check out this article to uplift your resume! Happy job hunting!

✍️ Written by Ishtiak Ahmed

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