## Enumerations ~~~ enum CompassPoint { case North case South case East case West } enum Planet { case Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune } var directionToHead = CompassPoint.West directionToHead = .East directionToHead = .South switch directionToHead { case .North: println("Lots of planets have a north") case .South: println("Watch out for penguins") case .East: println("Where the sun rises") case .West: println("Where the skies are blue") } // prints "Watch out for penguins" ~~~ ~~~ let somePlanet = Planet.Earth switch somePlanet { case .Earth: println("Mostly harmless") default: println("Not a safe place for humans") } // prints "Mostly harmless" ~~~ ~~~ enum Barcode { case UPCA(Int, Int, Int) case QRCode(String) } var productBarcode = Barcode.UPCA(8, 85909_51226, 3) productBarcode = .QRCode("ABCDEFGHIJKLMNOP”) switch productBarcode { case .UPCA(let numberSystem, let identifier, let check): println("UPC-A with value of \(numberSystem), \(identifier), \(check).") case .QRCode(let productCode): println("QR code with value of \(productCode).") } // prints "QR code with value of ABCDEFGHIJKLMNOP.” switch productBarcode { case let .UPCA(numberSystem, identifier, check): println("UPC-A with value of \(numberSystem), \(identifier), \(check).") case let .QRCode(productCode): println("QR code with value of \(productCode).") } // prints "QR code with value of ABCDEFGHIJKLMNOP." ~~~ ~~~ // raw values enum ASCIIControlCharacter: Character { case Tab = "\t" case LineFeed = "\n" case CarriageReturn = "\r" } enum Planet: Int { case Mercury = 1, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune } let earthsOrder = Planet.Earth.toRaw() // earthsOrder is 3 let possiblePlanet = Planet.fromRaw(7) // possiblePlanet is of type Planet? and equals Planet.Uranus let positionToFind = 9 if let somePlanet = Planet.fromRaw(positionToFind) { switch somePlanet { case .Earth: println("Mostly harmless") default: println("Not a safe place for humans") } } else { println("There isn't a planet at position \(positionToFind)") } // prints "There isn't a planet at position 9" ~~~