Inheritance - Java - page 446

Self-Test Exercises (continued)
12. Suppose B and D are as described in Self-Test Exercise 11. Is the following a legit-
imate method that can appear in the definition of the class D ?

public void demo2()
{
D object = new D();
object.doStuff(); //doStuff is inherited from B.
}

13. Suppose B and D are as described in Self-Test Exercise 11. Is the following a legit-
imate method that can appear in the definition of the class D ?

public void demo3()
{
B object = new B();
object.doStuff();
}

7.3 Programming with Inheritance

The devil is in the details.

COMMON SAYING

In the previous section, we described the basic idea and basic details about derived
classes. In this section, we continue that discussion and go on to discuss some more sub-
tle points about derived classes. In the process, we also discuss the class Object , which is
an ancestor class of all Java classes, and we describe a better way to define an equals
method.

TIP: Static Variables Are Inherited

Static variables in a base class are inherited by any derived classes. The modifiers public ,
private , and protected , and package access have the same meaning for static variables
as they do for instance variables. ■