Swiftly

Swift 5.6 references for busy coders

Switch (case)

Switch with equality

A default case is necessary when not all cases are covered.

func describe(animal: String) {
  switch animal {
  case "Owl", "Crane":
    print("\(animal) is a bird")
  case "Lion":
    print("\(animal) is a feline")
  case "Ant":
    print("\(animal) is an insect")
  default:
    print("\(animal) is something else")
  }
}

describe(animal: "Owl") // "A bird"
describe(animal: "Bear") // "Something else"

Switch with tuples

A default case is unnecessary when all cases are covered.

func describe(point: (Int, Int)) {
  switch point {
  case (0, 0):
    print("\(point) is at the origin")
  case (_, 0):
    print("\(point) is on the x-axis")
  case (0, _):
    print("\(point) is on the y-axis")
  case (_, _):
    print("\(point) is somewhere else")
  }
}

describe(point: (5, 0)) // "On x-axis"
describe(point: (11, 9)) // "Elsewhere"

Switch with enum

enum Beatle { case john, paul, george, ringo }

var myFavoriteBeatle = Beatle.john

switch myFavoriteBeatle {
case .john:
  print("My favorite played vocals & lead guitar.")
case .paul:
  print("My favorite played vocals & bass guitar.")
case .george:
  print("My favorite played lead & rhythm guitar.")
case .ringo:
  print("My favorite played the drums.")
}
// Output: "My favorite played vocals & lead guitar."

Switch with range

let userAge = 25

switch userAge {
case 0..<13:
  print("The user is a child.")
case 13..<18:
  print("The user is a teenager.")
case 18...Int.max:
  print("The user is an adult.")
default:
  print("Invalid age.")
}

// Output: "The user is an adult."

See also

Further reading