Chapter 12. Classes

CONTENTS

Section 12.1 Class Definitions and Declarations	430
Section 12.2 The Implicit this Pointer	440
Section 12.3 Class Scope	444
Section 12.4 Constructors	451
Section 12.5 Friends	465
Section 12.6 static Class Members	467
Chapter Summary	473
Defined Terms	473

In C++ we use classes to define our own abstract data types. By defining types that mirror concepts in the problems we are trying to solve, we can make our programs easier to write, debug, and modify.

This chapter continues the coverage of classes begun in Chapters 2 and 5. We'll cover in more detail the importance of data abstraction, which lets us hide the internal representation of an object while still allowing public operations to be performed on the object.

We'll also explain more about class scope, constructors, and the this pointer. We also introduce three new class-related features: friends, and mutable and static members.

Classes are the most important feature in C++. Early versions of the language were named "C with Classes," emphasizing the central role of the class facility. As the language evolved, support for building classes increased. A primary goal of the language design has been to provide features that allow programmers to define their own types that are as easy and intuitive to use as the built-in types. This chapter presents many of the basic features of classes.