If you're a Swift developer preparing for your next job interview, this page is perfect for you: I've collected over 150 of the top interview questions about iOS, Swift, UIKit, SwiftUI, and more, and also provided suggested approaches to answering each question.
These questions are used by companies around the world in their interviews. Not questions "like these" or "based on these" – companies literally use these exact questions. So, browsing through a few and testing yourself is a great way to prepare.
Questions are grouped by category, and I've also tried to provide some idea of difficulty using a traffic light system. Obviously my idea of "easy" or "hard" won't exactly match yours, but hopefully it at least lets you focus your attention more easily. To get started, select a category, then select a question that interests you.
Tip: For more kinds of interview preparation and career guidance, see my Swift Career Guide.
Questions that cover making apps easier to use for everyone.
Questions dealing with data and data structures.
UUID, and when might you use it?
Questions about design patterns, code architectures, and other programming approaches.
Questions about Apple frameworks and APIs beyond UIKit and SwiftUI.
UserDefaultsgood for? What is
UserDefaultsnot good for?
General questions about building for iOS itself, or UI questions that apply to both UIKit and SwiftUI.
UIColorhas values outside 0 to 1?
Questions that cover how you interact with Apple, other developers, designers, and more.
Questions about improving your apps to be faster, more efficient, less crashy, and similar.
Questions about how you store and send data.
Questions about the Swift language itself.
#errorcompiler directive do?
#if swiftsyntax do?
canImport()compiler condition do?
finalkeyword do, and why would you want to use it?
guardkeyword in Swift?
deferkeyword in Swift?
targetEnvironment()compiler condition do?
Questions about building apps with SwiftUI.
@Publishedproperty wrapper do?
@Stateproperty wrapper do?
Questions about building apps with UIKit.
Link copied to your pasteboard.