Introduction

In the preceding chapters, we introduced many basic terms and concepts of C++ objectoriented programming. We also discussed our program development methodology: We selected appropriate attributes and behaviors for each class and specified the manner in which objects of our classes collaborated with objects of C++ Standard Library classes to accomplish each program's overall goals.

In this chapter, we take a deeper look at classes. We use an integrated Time class case study in this chapter (three examples) and Chapter 10 (two examples) to demonstrate several class construction features. We begin with a Time class that reviews several of the features presented in the preceding chapters. The example also demonstrates an important C++ software engineering conceptusing a "preprocessor wrapper" in header files to prevent the code in the header from being included into the same source code file more than once. Since a class can be defined only once, using such preprocessor directives prevents multiple definition errors.

Next, we discuss class scope and the relationships among members of a class. We also demonstrate how client code can access a class's public members via three types of "handles"the name of an object, a reference to an object or a pointer to an object. As you will see, object names and references can be used with the dot (.) member selection operator to access a public member, and pointers can be used with the arrow (->) member selection operator.

We discuss access functions that can read or display data in an object. A common use of access functions is to test the truth or falsity of conditionssuch functions are known as predicate functions. We also demonstrate the notion of a utility function (also called a helper function)a private member function that supports the operation of the class's public member functions, but is not intended for use by clients of the class.


In the second example of the Time class case study, we demonstrate how to pass arguments to constructors and show how default arguments can be used in a constructor to enable client code to initialize objects of a class using a variety of arguments. Next, we discuss a special member function called a destructor that is part of every class and is used to perform "termination housekeeping" on an object before the object is destroyed. We then demonstrate the order in which constructors and destructors are called, because your programs' correctness depends on using properly initialized objects that have not yet been destroyed.

Our last example of the Time class case study in this chapter shows a dangerous programming practice in which a member function returns a reference to private data. We discuss how this breaks the encapsulation of a class and allows client code to directly access an object's data. This last example shows that objects of the same class can be assigned to one another using default memberwise assignment, which copies the data members in the object on the right side of the assignment into the corresponding data members of the object on the left side of the assignment. The chapter concludes with a discussion of software reusability.

Introduction to Computers, the Internet and World Wide Web

Introduction to C++ Programming

Introduction to Classes and Objects

Control Statements: Part 1

Control Statements: Part 2

Functions and an Introduction to Recursion

Arrays and Vectors

Pointers and Pointer-Based Strings

Classes: A Deeper Look, Part 1

Classes: A Deeper Look, Part 2

Operator Overloading; String and Array Objects

Object-Oriented Programming: Inheritance

Object-Oriented Programming: Polymorphism

Templates

Stream Input/Output

Exception Handling

File Processing

Class string and String Stream Processing

Web Programming

Searching and Sorting

Data Structures

Bits, Characters, C-Strings and structs

Standard Template Library (STL)

Other Topics

Appendix A. Operator Precedence and Associativity Chart

Appendix B. ASCII Character Set

Appendix C. Fundamental Types

Appendix D. Number Systems

Appendix E. C Legacy Code Topics

Appendix F. Preprocessor

Appendix G. ATM Case Study Code

Appendix H. UML 2: Additional Diagram Types

Appendix I. C++ Internet and Web Resources

Appendix J. Introduction to XHTML

Appendix K. XHTML Special Characters

Appendix L. Using the Visual Studio .NET Debugger

Appendix M. Using the GNU C++ Debugger

Bibliography



C++ How to Program
C++ How to Program (5th Edition)
ISBN: 0131857576
EAN: 2147483647
Year: 2004
Pages: 627

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