Top 30 iOS Interview Questions and Answers (2026 Edition)

iOS interviews in 2026 are different from what they were even two years ago. Companies now expect you to know SwiftUI as the primary framework, not just UIKit. They ask about Swift concurrency (async/await) as a baseline, not a bonus. And if you cannot explain @observable vs ObservableObject, that is a red flag. I have been through these interviews myself and helped others prepare. Here are the 30 questions that keep coming up, with answers that actually make sense. Swift Fundamentals 1. What is the difference between a struct and a class in Swift? Short answer: Structs are value types. Classes are reference types. Better answer: When you assign a struct to a new variable, Swift copies the entire value. When you assign a class instance, both variables point to the same object in memory. struct Point { var x : Int var y : Int } var a = Point ( x : 1 , y : 2 ) var b = a b . x = 10 // a.x is still 1 (independent copy) class Person { var name : String init ( name : String ) { self . name =