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To decide which rating instance method to use on, say, a
Movie instance, the Java compiler searches up from the
Movie class, through the subclass–superclass chain, to find the
first instance method named rating. For the Movie instance
example, the only rating instance method that the Java compiler
finds is the one in the Movie class.
On the other hand, the rating instance method selected by the Java
compiler to work on JamesBondMovie instances is the one in the
JamesBondMovie class, and the rating instance method in the
Movie class is said to be shadowed or
overridden
by that lower-level instance method.
Thus, you see the following result when your program calls the rating method.
For both the ordinary movie and the James Bond movie, the constructor in
the Movie class assigns 5 to the script,
acting, and direction instance variables.
public class Demonstrate {
public static void main (String argv[]) {
Movie m = new Movie();
System.out.println("The movie rating is " + m.rating());
JamesBondMovie jbm = new JamesBondMovie();
System.out.println("The James Bond movie rating is " + jbm.rating());
}
}
--- Result ---
Calling zero-parameter Attraction constructor
Calling zero-parameter Movie constructor
The movie rating is 15
Calling zero-parameter Attraction constructor
Calling zero-parameter Movie constructor
The James Bond movie rating is 20