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 = "	"
    case LineFeed = "
"
    case CarriageReturn = "
"
} 

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"