Chapter 18 Inheritance

18.11 Glossary


To represent one set of values using another set of values by constructing a mapping between them.

class attribute:

An attribute associated with a class object. Class attributes are defined inside a class definition but outside any method.

instance attribute:

An attribute associated with an instance of a class.


A method or function that provides a different interface to another function without doing much computation.


The ability to define a new class that is a modified version of a previously defined class.

parent class:

The class from which a child class inherits.

child class:

A new class created by inheriting from an existing class; also called a "subclass".

IS-A relationship:

A relationship between a child class and its parent class.

HAS-A relationship:

A relationship between two classes where instances of one class contain references to instances of the other.


A relationship between two classes where instances of one class use instances of the other class, but do not store them as attributes.

class diagram:

A diagram that shows the classes in a program and the relationships between them.


A notation in a class diagram that shows, for a HAS-A relationship, how many references there are to instances of another class.

data encapsulation:

A program development plan that involves a prototype using global variables and a final version that makes the global variables into instance attributes.