class Car {
    let horsepower: Int
    let color: String
    let numberOfCarDoors: Int

    init(horsepower: Int, color: String, numberOfCarDoors: Int) {
        self.horsepower = horsepower
        self.color = color
        self .numberOfCarDoors = numberOfCarDoors
    }

    func engineOn() {
        print("Engined turned on.")
    }

    func engineOff() {
        print("Engine turned off.")
    }
}

let myCar = Car(horsepower: 120, color: "green", numberOfCarDoors: 4)

myCar.engineOn() //Output: Engine turned on.

myCar.engineOff() //Output: Engine turned off.