/** Taken from Core Web Programming from
* Prentice Hall and Sun Microsystems Press,
* .
* © 2001 Marty Hall and Larry Brown;
* may be freely used or adapted.
*/
interface Barking {}
class Mammal {}
class Canine extends Mammal {}
class Dog extends Canine implements Barking {}
class Retriever extends Dog {}
public class InstanceOf {
public static void main(String[] args) {
Canine wolf = new Canine();
Retriever rover = new Retriever();
System.out.println("Testing instanceof:");
report(wolf, "wolf");
System.out.println();
report(rover, "rover");
System.out.println("\nTesting isInstance:");
Class barkingClass = Barking.class;
Class dogClass = Dog.class;
Class retrieverClass = Retriever.class;
System.out.println(" Does a retriever bark? " +
barkingClass.isInstance(rover));
System.out.println(" Is a retriever a dog? " +
dogClass.isInstance(rover));
System.out.println(" Is a dog necessarily a retriever? " +
retrieverClass.isInstance(new Dog()));
}
public static void report(Object object, String name) {
System.out.println(" " + name + " is a mammal: " +
(object instanceof Mammal));
System.out.println(" " + name + " is a canine: " +
(object instanceof Canine));
System.out.println(" " + name + " is a dog: " +
(object instanceof Dog));
System.out.println(" " + name + " is a retriever: " +
(object instanceof Retriever));
}
}
Aug 29