Classes & Structs

Swift has both class and struct for bundling data and behaviour together.

Example: a struct

struct Student {
    let name: String
    let track: String
}

let ada = Student(name: "Ada", track: "Frontend")
print("\(ada.name) is studying \(ada.track)")

Ada is studying Frontend

The key difference between the two: a class is a reference type — if you copy a class instance into another variable, both variables point at the exact same underlying object, so changing one changes what the other sees too. A struct is a value type — copies are completely independent, exactly like copying a plain number or string. Apple recommends structs by default, reaching for classes only when you specifically need shared, mutable state across multiple parts of your code — the opposite default from Java or C#, where classes are the only option for this kind of thing at all.