15 Inheritance

1. 15.1 Inheritance Basics 836

   1. Derived Classes 839

   2. Constructors in Derived Classes 847

   3. Pitfall: Use of Private Member Variables from the Base Class 850

   4. Pitfall: Private Member Functions Are Effectively Not Inherited 852

   5. The protected Qualifier 852

   6. Redefinition of Member Functions 855

   7. Redefining Versus Overloading 858

   8. Access to a Redefined Base Function 860

2. 15.2 Inheritance Details 861

   1. Functions That Are Not Inherited 861

   2. Assignment Operators and Copy Constructors in Derived Classes 862

   3. Destructors in Derived Classes 863

3. 15.3 Polymorphism 864

   1. Late Binding 865

   2. Virtual Functions in C++ 866

   3. Virtual Functions and Extended Type Compatibility 871

   4. Pitfall: The Slicing Problem 875

   5. Pitfall: Not Using Virtual Member Functions 876

   6. Pitfall: Attempting to Compile Class Definitions Without Definitions for Every Virtual Member Function 877

   7. Programming Tip: Make Destructors Virtual 877

1. Chapter Summary 879

2. Answers to Self-Test Exercises 879

3. Practice Programs 883

4. Programming Projects 886

With all appliances and means to boot.

WILLIAM SHAKESPEARE, King Henry IV, Part III

Introduction

Object-oriented programming is a popular and powerful programming technique. Among other things, it provides for a new dimension of abstraction known as inheritance. This means that a very general form of a class can be defined and compiled. Later, more specialized versions of that class can be defined and can inherit all the properties of the previous class. Facilities for inheritance are available in all versions of C++.

Prerequisites

Section 15.1 uses material from Chapters 2 to 8 and 10 to 12. Sections 15.2 and 15.3 use material from Chapters 9 and 13 in addition to Chapters 2 to 8, 10 to 12, and Section 15.1.