Composition

 

 

Composition은 합성이라는 뜻으로 class안에서 class를 사용하는 것을 의미한다.

 

 

 

class Car

class Car(val name: String, val power:String){

    private var engine = Engine(power)

    fun startEngine() = engine.start()
    fun stopEngine() = engine.stop()

}

class Engine

class Engine(power: String){
    fun start() = println("Engine has been started")
    fun stop() = println("Engine has been stopped")
}

함수호출부

 

fun main(args: Array<String>) {

    val car = Car("BMW", "100hp")
    car.startEngine()
    car.stopEngine()

}