swift - The Factory Method Pattern
|
class RentalCar { private var nameBV:String; private var passengersBV:Int; private var priceBV:Float;
private init(name:String,passengers:Int,price:Float) { self.nameBV = name; self.passengersBV = passengers; self.priceBV = price; }
final var name:String { get { return nameBV; }} final var passengers:Int { get { return passengersBV; }}; final var pricePerDay:Float { get { return priceBV; }};
class func createRentalCar(passengers:Int) -> RentalCar? { var carImpl:RentalCar.Type?; switch (passengers) { case 0...3: carImpl = Compact.self; case 4...8: carImpl = SUV.self default: carImpl = nil; } return carImpl?.createRentalCar(passengers); } } class Compact : RentalCar {
private convenience init() { self.init(name: "VW Golf",passengers: 3,price: 20); }
private override init(name: String,passengers: Int,price: Float) { super.init(name: name,passengers: passengers,price: price); }
override class func createRentalCar(passengers:Int) -> RentalCar? { if (passengers < 2) { return sharedInstance; } else { return SmallCompact.sharedInstance; } }
class var sharedInstance:RentalCar { get { struct SingletonWrapper { static let singleton = Compact(); } return SingletonWrapper.singleton; } } } class SmallCompact : Compact { private init() { super.init(name: "Ford Fiesta",price: 15); }
override class var sharedInstance:RentalCar { get { struct SingletonWrapper { static let singleton = SmallCompact(); } return SingletonWrapper.singleton; } } } class SUV : RentalCar { private init() { super.init(name: "Cadillac Escalade",passengers: 8,price: 75); } override class func createRentalCar(passengers:Int) -> RentalCar? { return SUV(); } } （编辑：李大同） 【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容! |