362: Mainline

With a rating method installed in the Movie class and the Symphony class, both of which implement the RatingInterface interface, you can use the rating method with either a Movie instance or Symphony instance assigned to a RatingInterface variable; the rating is computed by the methods defined in the Movie or Symphony class:

public class Demonstrate { 
 public static void main (String argv[]) { 
  // Movie instance assigned to x: 
  RatingInterface x = new Movie (5, 7, 7); 
  System.out.println("The movie's rating is " + x.rating()); 
  // Symphony instance assigned to x: 
  x = new Symphony (7, 5, 5); 
  System.out.println("The symphony's rating is " + x.rating()); 
 } 
}