枚举基本使用
表述一组值
枚举相当于创建了一种新的数据类型，而类型的取值由里面的case值进行表征
enum CompassPoint { // 大写开头 case north,west,east,south }
enum GameEnding { case Win case Lose case Draw } var yourScore:Int = 100 var enemyScore:Int = 100 var thisGameEnding:GameEnding if yourScore > enemyScore {thisGameEnding = GameEnding.Win} else if yourScore == enemyScore {thisGameEnding = GameEnding.Draw} else {thisGameEnding = .Lose} //可省略GameEnding switch thisGameEnding { case .Win: print("win") case .Draw: print("Draw") case .Lose: print("Lose") }
enum VowleCharacter:Character { case A = "a" case E = "e" case I = "i" case O = "o" case U = "u" } let vowelA = VowleCharacter.A var userInputCharacter:Character = "a" if userInputCharacter == vowelA.rawValue { print("it is an 'a'") //"it is an 'a'\n" }else { print("it is not an 'a'") }
灵活使用
enum Barcode { case UPCA(Int,Int,Int,Int) case QRCode(String) //将枚举变量QRCode关联为String类型 } let productCodeA = Barcode.UPCA(4, 102, 306, 8) let productCodeB = Barcode.QRCode("This is a infomation") switch productCodeA { case .UPCA(let numberSystem,let manufacture,let identifier,let check): print("UPC-A with value of \(numberSystem), \(manufacture), \(identifier),\(check).") //"UPC-A with value of 4, 102, 306,8.\n" case .QRCode(let productCode): print("QRCode with value of \(productCode).") }
