C - Program - 2e - Chapter01.pdf - po ang - Januszek66

C++ Overview and

Software Development

CHAPTER OBJECTIVES

Introduce this text to the reader.

KEY TERMS AND CONCEPTS

ANSI/ISO standard

C++ class

compiler

cross-platform code libraries

functions

linker

object

object-oriented program

open source software

operators

pointers

portable language

references

software development steps

software development skill set

source code

standardized libraries

structured programming

top-down

Visual C++ 2005

Present the history and an overview of the C and C++

languages.

Illustrate the concept of object-oriented programming.

Compare structured program design and object-oriented pro-

gram design.

Help the programmer begin thinking about all aspects of build-

ing software.

Welcome!

Y ou are about to embark on a wonderful journey. Learning to write computer

programs with the C++ programming language will bring you a wonderful

sense of accomplishment. When you become an efficient C++ developer,

technical career doors will open for you and many programming paths will be-

come available. C++ is a cornerstone in today’s programming environment.

Whether you are writing controllers for robots, implementing elegant user inter-

faces, building high-speed graphics for games, web services, interfacing into

databases, or learning the C++, C, or Java programming language for Internet

and Web application, C++ is where it all starts.

But beware! Programming—in any language—is not for everyone. In the

journey there are often speed bumps, potholes, clear-air turbulence, and fog. A

successful programmer uses many skills, including logical thinking and trou-

bleshooting. At times, success seems to depend on just plain luck. If you are al-

ready familiar with another programming language and are now learning C++,

you are aware of all these factors. If C++ is your first programming language, you

will find these pearls of wisdom to be true soon enough.

Software Developer Skill Set

Aside from learning C++, there are several other skills a student must learn to be

a successful software developer and to contribute fully to a development or

maintenance job. A few of these skills are listed in Table 1-1.

A software developer must also be a student of other fields. For any software

job, the developer must understand the underlying concepts of the software while

also working closely with non-software experts on a project. For example, to write

an inventory control and tracking system for an international company, the soft-

ware team must have a good idea of all aspects of the business. If you are writing a

program to handle bad debt for a company, you will need to know the laws and

company policies concerning debt. Software developers are not expected to be

experts in everything, but they should expect to keep learning new things long

after school is out.

Chapter 1

❚

C++ Overview and Software Development

❚

TABLE 1-1

Software Developer’s Skill Set

Skill

Where It Is Used

Documentation

All software needs to be documented well and should be easy to read. Docu-

mentation is written into the source code as comments and describes what the

program is doing, the logic that is used, how the user interacts with the program,

and any special methods used. You should write your software assuming that it will

be used for years to come. Can someone read your software and know what you

were doing?

Communication

Software developers must be able to communicate with team members, cus-

tomers, and end users. Software projects often go through several design stages.

Formal design and requirements documents are written before any code is built.

Quick learners

Software developers often work with experts in other fields who need to have soft-

ware written. The software developer must gain some level of understanding of

the new concepts before he or she is able to build the software. Often program-

ming requires the use of mathematics. The programmer should be familiar with

mathematical concepts.

Debugging

It is vitally important to learn debugging skills when developing software. Debug-

gers aid in finding problems in software.

Troubleshooting

Debugging “broken” code is common. Good analysis/troubleshooting skills are in-

valuable.

Testing

Always think about how to test your software. Are you covering all the cases? Test-

ing is one of the most important aspects of software development, but it is the

most often neglected.

A Few Details Concerning This Text

Concepts, Order of Presentation Chapters 2 through 6 present the nuts

and bolts of the C/C++ language including an introduction to object-oriented

concepts in Chapter 1. In Chapter 2, we begin using classes provided in the C++

standard libraries and learn how to get data in and out of a program. We write

short programs that use different types of data, practice writing math statements.

In Chapter 3 we need to be able to have our code perform logical and condition-

al statements and loops. Chapter 4 teaches us how to separate our code into indi-

vidual modules known as functions. We explore the various ways C++ lets us

write functions, including overloading, and default parameter lists. In Chapter 5,

we expand our discussion of functions by presenting an introduction to refer-

ences and pointers. Pointers and references are handy little devices found every-

where in C++ code. Chapter 6 introduces the concept of an array—a list or

grouping of data variables and, finally, Chapters 7 and 8 provide the tools for you

to write your own classes.

Although we begin writing our own classes and using our objects in Chapter 7,

we begin using several C++ classes right from the start! Chapter 1 introduces an

easy way to understand classes and objects, and then we use the C++ string class in

Chapter 2. In Chapter 3, we begin using the C++ vector class. These classes give us

Johnston’s Rules for Programmers

the ability to build interesting C++ programs right away. By the time we reach

Chapter 7, we are familiar with classes. The mechanics of writing object-oriented

software are based on the concepts we’ve been studying in the first several chap-

ters. In the latter chapters, we write several programs using many of the classes we

write as well as the classes C++ gives us.

Accompanying CD with This Book One compact disc is included with this

book. On it is a copy of the Microsoft Visual C++ 2005 Express Edition , which

may be installed on a personal computer and used to build and run C++ pro-

grams. This software includes the Visual Studio C++ development tools as well as

an excellent C++ Language Reference. Appendix A, “Getting Started with Visual

C++ 2005 Express Edition,” covers the system requirements, software installation,

all of the necessary steps to create and run a simple project, and how to access the

help feature. (The debugger tool is described in Appendix I, “Microsoft Visual

C++ 2005 Express Ediiton Debugger.”)

Microsoft Visual C++

2005

Microsoft’s C++ de-

velopment environ-

ment

Program Source Code The source code for all the program examples in this

text are available on the text's website. These examples are organized into

Microsoft Visual C++ 2005 project folders, and each is located in its respective

chapter folder. The project folders should be copied onto the reader’s hard drive.

The projects may be opened using Visual C++ 2005, or the source files can be

copied and compiled in other C++ environments.

ISO C++, Not Visual C++ The programs included in this text are written

according to the International Standards Organization (ISO) C++ standards.

You may run (or modify and run) these programs on any computer system that

has ISO standard C++ software. The Microsoft Visual C++ 2005 software is

included so that you may load it on your personal computer at home and prac-

tice writing C++ programs. One appendix covers how to install and get started

with this software. Another appendix covers how to use the debugger in Visual

C++ 2005. We will be creating and running our programs by using the Console

Application.

Program Examples, Output, Errors, and Warnings This book also includes

a wide variety of program examples—short five-liners to multifile, multi-object,

medium-size programs. Some are complete programs, and the reader is welcome to

use them as starting points for further expansion, such as accessing the computer sys-

tem time as a seed for the random number generator. You will find many examples of

code that are written incorrectly and hence do not build and execute. (Sometimes

seeing the wrong way is more informative than seeing the right way.) We illustrate the

wrong code along with the software error and/or warning messages.

Johnston’s Rules for Programmers

As a team member of a commercial firm engaged in building and developing

software, I am acquainted with technology skills needed in the marketplace. And

as a member of the faculty of a community college, I have learned ways to help

students master these skills. Teaching beginning C and C++ students for many

Chapter 1

❚

C++ Overview and Software Development

years has brought an understanding of the trials and tribulations that the new

C++ student encounters.

Drafts of the first edition of this text were used for four semesters by beginning

and advanced C++ programming students. This second edition revision also used C++

programming students as test-drivers, who worked through new ideas, concepts, and

programs. Past students also volunteered to help with this second edition. My begin-

ning C++ students are excellent test subjects and proved to be adept at using C++

classes in their second program. They followed the introductory examples and discus-

sions here, and were soon showing that they were apt object users.

While test-driving the material in this book, these first semester program-

ming students were quite open about what they needed in the text to aid them in

learning to program in C++. They told me what they liked and did not like, and

what was helpful and what was confusing. Past students who are now working as

C/C++ programmers or are continuing their education have provided even more

suggestions and advice.

A common theme for all these students is their belief in the set of rules we

develop at the beginning of each programming course. We refer to them as either

the “Nine Rules for Programmers” or the “Johnston Rules for Programmers.”

They are:

Keep your cool (don’t get mad).

Work when you are rested (don’t program when you are tired).

KISS your software (keep it simple, sweetie).

Give help/get help.

Study and know the rules for the language (syntax).

Learn the development environment and tools (we’ll concentrate on

Visual C++).

Understand the problem you are trying to solve.

Build and test your software in steps.

Save early/save often (back up your computer programming files often).

One more rule might emphasize, “Patience, patience, patience.” You can apply

this maxim immediately, as several topics need to be covered before we reach the

core of the C++ language. Two of my students like to say that there is no crying in

baseball, but they’re not so sure about programming! It is important to follow the

above rules for programming so you’re not crying at your computer. Read on,

have fun! Principles that now seem disjointed will come together as you practice,

practice, practice your programming.

1.1

What Is C and What Is C++?

The C language was developed originally by Bell Laboratories and was stan-

dardized by the American National Standards Institute (ANSI) in 1989. In

1990, the International Standards Organization (ISO) adopted the ANSI stan-

dard. You can think of the ISO Standard as the governing laws for C/C++. These

ISO Standards dictate the correct form of C/C++ statements, and how aspects of

the language must work.

ANSI

American National

Standards Institute

ISO

International Stan-

dards Organization

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