Kodebits Day 10: Protocol Extension

What does this print?

protocol Greet {
  var name: String { get }
}
extension Greet {
  func hi() -> String {
    "Hi, \(name)"
  }
}
struct Dev: Greet {
  let name: String
}
print(Dev(name: "Sam").hi())

Try it in the online Swift Playground →

[spoiler title="Solution"]

Answer:

Hi, Sam

Explanation:

Dev gets hi() from the protocol extension, which interpolates name.

[/spoiler]

Further Reading

• Use Protocol Extension in Swift
• Use Protocol-oriented Programming in Swift