A good answer might be:

1. You should not have to write the same code more than once.
2. To maintain consistency between related classes.

So far the video rental application has two classes: VideoTape and Movie. Say that you wanted to create a new class, MusicVideo that will be like VideoTape but will have two new instance variables: artist (the name of the performer) and category ("R&B", "Pop", "Classical", "Other" ). Both of these will be Strings. The MusicVideo class will need its own constructor and its own show() method. Here is the base class:

class VideoTape { String title; // name of the item int length; // number of minutes boolean avail; // is the tape in the store? // constructor public VideoTape( String ttl, int lngth ) { title = ttl; length = lngth; avail = true; } public void show() { System.out.println( title + ", " + length + " min. available:" + avail ); } }

The new class will look something like this:

class ______________ extends _________________ { String ______________; // the artist String ______________; // the music category // constructor will go here (skip for now) // show method will go here (skip for now) }

QUESTION 14:

Write a definition of the class MusicVideo which extends the parent class Video. For now, leave out the constructor and the show() method.