Chapter 1. Introduction to Computers, the Internet and Visual C

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Chapter 1. Introduction to Computers, the Internet and Visual C#

The chief merit of language is clearness.


High thoughts must have high language.


Our life is frittered away with detail. . . . Simplify, simplify.

Henry David Thoreau

My object all sublime I shall achieve in time.

W. S. Gilbert

Man is still the most extraordinary computer of all.

John F. Kennedy


In this chapter you will learn:

  • Basic hardware and software concepts.

  • The different types of programming languages.

  • Which programming languages are most widely used.

  • The history of the Visual C# programming language.

  • Some basics of object technology.

  • The history of the UMLthe industry-standard object-oriented system modeling language.

  • The history of the Internet and the World Wide Web.

  • The motivation behind and an overview of the Microsoft's .NET initiative, which involves the Internet in developing and using software systems.

  • To test-drive a Visual C# 2005 application that enables you to draw on the screen.

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What Is a Computer?


Computer Organization


Early Operating Systems


Personal Computing, Distributed Computing and Client/Server Computing


Hardware Trends


Microsoft's Windows® Operating System


Machine Languages, Assembly Languages and High-Level Languages




C, C++, Java and Visual Basic


Other High-Level Languages


The Internet and the World Wide Web


Extensible Markup Language (XML)


Microsoft's .NET


The .NET Framework and the Common Language Runtime


Test-Driving a C# Application


(Only Required Section of the Case Study) Software Engineering Case Study: Introduction to Object Technology and the UML




Web Resources



Self-Review Exercises

Answers to Self-Review Exercises


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1.1. Introduction

Welcome to Visual C# (pronounced "C-Sharp") 2005! We have worked hard to provide you with accurate and complete information regarding this powerful computer programming language, which from this point forward, we shall generally refer to simply as C#. C# is appropriate for technically oriented people with little or no programming experience and for experienced programmers for use in building substantial information systems. Visual C# 2005 How to Program, Second Edition is an effective learning tool for each of these audiences. We hope that working with this book will be an informative, challenging and entertaining learning experience for you.

How can one book appeal to both novices and skilled programmers? The core of this book emphasizes achieving program clarity through the proven techniques of object-oriented programming (OOP) and event-driven programming. Nonprogrammers learn basic skills that underlie good programming; experienced developers receive a rigorous explanation of the language and may improve their programming styles. Perhaps most important, the book presents hundreds of complete, working C# programs and depicts their inputs and outputs. We call this the live-code approach. All of the book's examples may be downloaded from and

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Computer use is increasing in almost every field of endeavor. Computing costs have been decreasing dramatically due to rapid developments in both hardware and software technologies. Computers that might have filled large rooms and cost millions of dollars a few decades ago can now be inscribed on silicon chips smaller than a fingernail, costing a few dollars each. Fortunately, silicon is one of the most abundant materials on earthit's an ingredient in common sand. Silicon chip technology has made computing so economical that about a billion general-purpose computers are in use worldwide, helping people in business, industry and government, and in their personal lives.

We hope that you will enjoy learning with Visual C# 2005 How to Program, Second Edition. You are embarking on a challenging and rewarding path. If you have any questions as you proceed, please send e-mail to

To keep current with C# developments at Deitel & Associates and to receive updates to this book, please register for our free e-mail newsletter, the Deitel® Buzz Online, at