Java Reference
In-Depth Information
9
Object-Oriented
Programming: Inheritance
Say not you know another
entirely,
till you have divided an
inheritance with him.
—Johann Kasper Lavater
This method is to define as the
number of a class the class of all
classes similar to the given class.
—Bertrand Russell
Objectives
In this chapter you'll:
Understand inheritance and
how to use it to develop new
classes based on existing
classes.
■
Learn the notions of
superclasses and subclasses
and the relationship between
them.
■
Use keyword
extends
to
create a class that inherits
attributes and behaviors from
another class.
■
Use access modifier
protected
in a superclass
to give subclass methods
access to these superclass
members.
■
Access superclass members
with
super
from a subclass.
■
Learn how constructors are
used in inheritance
hierarchies.
■
Learn about the methods of
class
Object
, the direct or
indirect superclass of all
classes.
■
