If a parent and a child both have a feature (like a title), then the feature should be put in the parent and inherited by the child.
Movie
Here is a version of main()
that makes use of the two classes (original versions):
public class VideoStore { public static void main ( String args[] ) { Video item1 = new Video("Microcosmos", 90 ); Movie item2 = new Movie("Jaws", 120, "Spielberg", "PG" ); System.out.println( item1.toString() ); System.out.println( item2.toString() ); } }
The program prints:
Microcosmos, 90 min. available:true Jaws, 120 min. available:true
The statement item2.toString()
calls the toString()
method
of item2
.
This method was inherited without change from the class
Video
.
This is what it looks like:
public String toString() { title + ", " + length + " min. available:" + avail ; }
It does not use the new variables that Movie
objects have,
so the director and rating are not printed out.
It would be worthwhile (of course) to download a play with the complete program. Here is the link: Video Store.
Why not change toString()
in Video
to this:
public String toString() { title + ", " + length + " min. available:" + avail + "dir: " + director + ", rating: " + rating ); }