#41: Struct or Class in Swift?

A good default in Swift is: start with a struct.

Structs are value types, which makes copying behavior explicit and usually easier to reason about. They also compose well with immutable design.

struct User {
    var name: String
}

Use a class when you need one of these features:

• shared mutable identity
• reference semantics
• inheritance
• Objective-C interoperability

final class ImageCache {
    private var storage: [URL: Data] = [:]
}

If you are unsure, a struct is often the safer first choice.