/*****************************************************/ // INHERIT0 // The following code is an example of a hierarchy // that classes might form. // Create a bunch of classes: class A {} class B extends A {} class C extends A {} final class D extends B {} // $final$ prevents // class E extends D {} // inheritance // Here is the Class Hierarchy: // // A // / \ // B C // | // D // // + Note how you write superclasses above subclasses. // + Draw links as arrows pointing upwards. // + A superclass may have multiple subclasses, // but each subclass may have only ONE superclass. // + Java does not have "multiple inheritance." public class inherit0 { public static void main(String[] args) { B b1 = new B(); A b2 = new B(); // pp 478-479 // B b3 = new A(); // illegal! see pg 479 // Using "built-in" method $getClass()$, which // returns the name of the actual class of the // object: System.out.println(b1.getClass()); System.out.println(b2.getClass()); } } /* output: B B */