8. Main Driver

• 
  //A Very Simple Example
  class MainDriver
  {
      public static void main(String[] args)
      {
          System.out.println("The area is: ");
          Circle circle = new Circle(5);
          Rectangle rectangle = new Rectangle(4, 5);
          System.out.println( getArea( circle ) + getArea( rectangle ) );
      }
  
      static double getArea( Shape shape )
      {
          return shape.getArea();
      }
  }
  
  

• Any Shape-derived object we pass to getArea( ) java method of the MainDriver program will behave differently.

• It depends on the type of shape which we pass as the parameter.