Beginning Programming for Dummies

433 Pages·2004·7.68 MB·English

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Beginning
Programming
FOR
DUMmIES
‰
3
RD EDITION
by Wallace Wang
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Beginning Programming For Dummies®, 3rd Edition
Published by
Wiley Publishing, Inc.
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Hoboken, NJ 07030-5774
Copyright ©2004 by Wiley Publishing, Inc., Indianapolis, Indiana
Published by Wiley Publishing, Inc., Indianapolis, Indiana
Published simultaneously in Canada
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Library of Congress Control Number: 2003114793
ISBN: 0-7645-4997-9
Manufactured in the United States of America
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About the Author
After spending his first two post-college years working for a dead-end corpo-
ration that encouraged its employees to use euphemisms to disguise the fact
that they were manufacturing nuclear weapons with the potential to wipe out
most forms of life on the planet, Wallace Wang decided that his life was meant
to be spent doing something more exciting than existing in a corporate culture
that stifled freedom and democracy while building missiles ostensibly to
protect freedom and democracy. With the thought of escape in his mind, he
bought one of the first IBM personal computers on the market—and quickly
realized that the accompanying computer manuals were completely incom-
prehensible.
After deciphering the manuals and learning to master the arcane commands
of the ancient MS-DOS version 1.25 operating system, Wallace decided to pub-
lish fragments of his notes in a local computer magazine for the amusement
of others—and to provide an alternative source of income for his eventual
departure from the mentally suffocating environment of the military-industrial
complex.
After people began responding favorably to his introductory computer maga-
zine articles, he continued writing more, eventually turning to writing full-time.
For the first time, he managed to earn a living in a job that didn’t involve devel-
oping something that could blow up people who happen to live in another part
of the world.
Today, the author is happily pursuing a dual career in the book publishing
industry and the stand-up comedy industry. His eventual goal is to convince
people that enjoying yourself while learning is all right. In the meantime, he
plans to continue making fun of any idiots and morons who happen to get in
his way.
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Dedication
This book is dedicated to all the wonderful people I’ve met along the path of
life, including . . .
Cassandra (my wife), Jordan (my son), and Bo, Scraps, Tasha, and Nuit
(our cats).
Lily Carnie, the only person I know who can truly see both sides of the story.
All the friendly folks I’ve met while performing at the Riviera Comedy Club,
located at the Riviera Hotel & Casino in Las Vegas: Steve Schirripa (who also
appears on the HBO show, The Sopranos, which you can read about at www.
hbo.com/sopranos), Don Learned, Bob Zany, Gerry Bednob, Bruce Clark,
Darrell Joyce, Tony Vicich, and Kip Addotta. The next time you’re visiting Las
Vegas, drop by the Riviera and watch a comedy show. Then dump some money
in a slot machine on the way out to ensure that the Riviera Hotel & Casino
continues making enough money to keep its comedy club open.
Patrick DeGuire, who helped me form Top Bananas (at www.topbananas.com),
our company devoted to providing clean, quality stand-up comedy to the
wonderfulpeople in San Diego. Thanks must also go to Leo (the man, the
myth, thelegend) Fontaine, Chris (the Zooman) Clobber, and Dante (who gets
excited just to see his name in a book).
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Author’s Acknowledgments
If it weren’t for Matt Wagner and Bill Gladstone at Waterside Productions, I
may never have written this book (and someone else may have). That’s why I
don’t mind paying these guys 15 percent of the book royalties so that they
can afford to buy their groceries.
Additional thanks go to Allen Wyatt (the technical reviewer) for making sure
that everything in this book is accurate, and to Cassandra (my wife) for
putting up with multiple computers that (from her point of view) seem to
spontaneously appear and disappear from the house at random. Each time a
computer disappears, a more advanced model appears that promises more
speed and hard disk space but still never seems to have more speed or as
much room as the previous computer model that it replaced.
A final note of thanks must go to the Chinese and Russians who’ve translated
my other books, Microsoft Office For Dummiesand Visual Basic For Dummies.
The Chinese and Russian editions are the only foreign translations of my books
ever to include my previously published references to General Dynamics as a
“bomb factory.” Whether translators in other countries purposely omitted this
humorous reference or whether it’s just a coincidence that only the Chinese
and Russian editions included this reference is unknown.
Still, this fact alone provides an endless source of amusement to think that
Chinese and Russian readers are privy to an American joking about his
country’s nuclear missile factories, while readers in other countries are not.
For that reason alone, the Chinese and Russian translators of my books have
my eternal gratitude and blessing, not because they happen to be Chinese or
Russian, but because they appear to be able to appreciate a joke.
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Publisher’s Acknowledgments
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Contents at a Glance
Introduction ................................................................1
Part I: Programming a Computer ...................................7
Chapter 1: Learning Computer Programming for the First Time ................................9
Chapter 2: All about Programming Languages ............................................................19
Chapter 3: How to Write a Program ..............................................................................37
Chapter 4: The Tools of a Computer Programmer ......................................................47
Part II: Learning Programming with Liberty BASIC ......59
Chapter 5: Getting Your Hands on a Real Language: Liberty BASIC .........................61
Chapter 6: Handling Input and Output .........................................................................71
Chapter 7: Variables, Constants, and Comments ........................................................79
Chapter 8: Crunching Numbers and Playing with Strings ..........................................95
Chapter 9: Making Decisions with Control Statements ............................................111
Chapter 10: Repeating Yourself with Loops ...............................................................129
Part III: Advanced Programming
with Liberty BASIC ..................................................139
Chapter 11: Writing Large Programs by Using Subprograms ..................................141
Chapter 12: Drawing Pictures and Making Noise ......................................................161
Chapter 13: Saving and Retrieving Stuff in Files ........................................................175
Chapter 14: Creating a User Interface .........................................................................191
Chapter 15: Debugging Programs ................................................................................215
Part IV: Dealing with Data Structures .......................223
Chapter 16: Storing Stuff in Arrays ..............................................................................225
Chapter 17: Lumping Related Data in Records ..........................................................235
Chapter 18: Linked Lists and Pointers ........................................................................241
Chapter 19: Playing with Object-Oriented Programming .........................................255
Part V: Algorithms: Telling the
Computer What to Do ...............................................267
Chapter 20: Sorting .......................................................................................................269
Chapter 21: Searching ...................................................................................................287
Chapter 22: Optimizing Your Code ..............................................................................299
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Part VI: Internet Programming ..................................309
Chapter 23: Playing with HTML ...................................................................................311
Chapter 24: Making Interactive Web Pages with JavaScript ....................................339
Chapter 25 Using Java Applets on Web Pages ...........................................................351
Part VII: The Part of Tens .........................................359
Chapter 26: Ten Cool Programming Careers ..............................................................361
Chapter 27: Ten Additional Programming Resources ...............................................371
Appendix: About the CD ...............................................................................................387
Bonus Chapter: Programming in Python....................CD-1
Index ......................................................................395
End-User License Agreement .....................................413
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Table of Contents
Introduction .................................................................1
Who Should Buy This Book ...........................................................................2
How This Book Is Organized ..........................................................................2
Part I: Programming a Computer .........................................................2
Part II: Learning Programming with Liberty BASIC ...........................3
Part III: Advanced Programming with Liberty BASIC ........................3
Part IV: Dealing with Data Structures .................................................3
Part V: Algorithms: Telling the Computer What to Do .....................4
Part VI: Internet Programming .............................................................4
Part VII: The Part of Tens .....................................................................4
How to Use This Book ....................................................................................5
Foolish assumptions .............................................................................5
Icons used in this book .........................................................................5
Part I: Programming a Computer ...................................7
Chapter 1: Learning Computer Programming for the First Time . . . . . .9
Why Learn Computer Programming? ...........................................................9
How Does a Computer Program Work? ......................................................13
Programming is problem-solving ......................................................14
Programming isn’t difficult; it’s just time-consuming .....................15
What Do I Need to Know to Program a Computer? ..................................16
Chapter 2: All about Programming Languages . . . . . . . . . . . . . . . . . . .19
Why So Many Different Programming Languages? ...................................19
The joy of assembly language ............................................................20
C: The portable assembler .................................................................22
High-level programming languages ...................................................24
Rapid Application Development (RAD)
programming languages ..................................................................27
Database programming languages ....................................................29
Scripting programming languages ....................................................30
Web-page programming languages ...................................................32
So What’s the Best Programming Language to Learn? .............................34
Chapter 3: How to Write a Program . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Before You Write Your Program ..................................................................37
The program’s users ...........................................................................38
The target computer ...........................................................................38
Your own programming skill ..............................................................39