Method Access

[Malk Boy]

My question is how do I access the methods of the engine class in the control class when I pass an object car to control.

Thanks for any help

public class Car
{
Engine e;

public car ()
{
e = new Engine();
}

public static void main ( String[] args )
{
Car c = new Car();
Control ctrl = new Control ( c );
ctrl.runSystem();
}
}

[marc weber]

Just connect the dots: CarRef.EngineRef.method();

class Engine {
  public void vroom() {
    System.out.println("Vroom!");
  }
}
 
class Control {
  Car cc;
  public Control(Car c) {
    cc = c;
  }
  public void runSystem() {
    cc.e.vroom();
  }
}
 
public class Car {
  Engine e;
 
  public Car() {
    e = new Engine();
  }
 
  public static void main(String[] args){
    Car c = new Car();
    Control ctrl = new Control(c);
    ctrl.runSystem();
  }
}

[marc weber]

As an aside, note that this version of Car could be streamlined to...

public class Car {
  Engine e = new Engine();
 
  public static void main(String[] args){
    (new Control(new Car())).runSystem();
  }
}