Burd - Beginning Programming with Java For Dummies

Beginning Programming with JavaFor Dummies, 5th Edition

Published by: John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030-5774, www.wiley.com

Copyright 2017 by John Wiley & Sons, Inc., Hoboken, New Jersey

Published simultaneously in Canada

No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the Publisher. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions .

Trademarks: Wiley, For Dummies, the Dummies Man logo, Dummies.com, Making Everything Easier, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and may not be used without written permission. Java is a registered trademark of Oracle America, Inc. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book.

LIMIT OF LIABILITY/DISCLAIMER OF WARRANTY: THE PUBLISHER AND THE AUTHOR MAKE NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY OR COMPLETENESS OF THE CONTENTS OF THIS WORK AND SPECIFICALLY DISCLAIM ALL WARRANTIES, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE. NO WARRANTY MAY BE CREATED OR EXTENDED BY SALES OR PROMOTIONAL MATERIALS. THE ADVICE AND STRATEGIES CONTAINED HEREIN MAY NOT BE SUITABLE FOR EVERY SITUATION. THIS WORK IS SOLD WITH THE UNDERSTANDING THAT THE PUBLISHER IS NOT ENGAGED IN RENDERING LEGAL, ACCOUNTING, OR OTHER PROFESSIONAL SERVICES. IF PROFESSIONAL ASSISTANCE IS REQUIRED, THE SERVICES OF A COMPETENT PROFESSIONAL PERSON SHOULD BE SOUGHT. NEITHER THE PUBLISHER NOR THE AUTHOR SHALL BE LIABLE FOR DAMAGES ARISING HEREFROM. THE FACT THAT AN ORGANIZATION OR WEBSITE IS REFERRED TO IN THIS WORK AS A CITATION AND/OR A POTENTIAL SOURCE OF FURTHER INFORMATION DOES NOT MEAN THAT THE AUTHOR OR THE PUBLISHER ENDORSES THE INFORMATION THE ORGANIZATION OR WEBSITE MAY PROVIDE OR RECOMMENDATIONS IT MAY MAKE. FURTHER, READERS SHOULD BE AWARE THAT INTERNET WEBSITES LISTED IN THIS WORK MAY HAVE CHANGED OR DISAPPEARED BETWEEN WHEN THIS WORK WAS WRITTEN AND WHEN IT IS READ.

For general information on our other products and services, please contact our Customer Care Department within the U.S. at 877-762-2974, outside the U.S. at 317-572-3993, or fax 317-572-4002. For technical support, please visit https://hub.wiley.com/community/support/dummies .

Wiley publishes in a variety of print and electronic formats and by print-on-demand. Some material included with standard print versions of this book may not be included in e-books or in print-on-demand. If this book refers to media such as a CD or DVD that is not included in the version you purchased, you may download this material at http://booksupport.wiley.com . For more information about Wiley products, visit www.wiley.com .

Library of Congress Control Number: 2017944007

ISBN: 978-1-119-23553-8 (pbk); 978-1-119-23556-9 (ebk); 978-1-119-23554-5 (ebk)

1. Table of Contents

Whats your story?

• Are you a working stiff, interested in knowing more about the way your companys computers work?
• Are you a student who needs some extra reading in order to survive a beginning computer course?
• Are you a typical computer user youve done lots of word processing and you want to do something more interesting with your computer?
• Are you a job seeker with an interest in entering the fast-paced, glamorous, high-profile world of computer programming (or, at least, the decent-paying world of computer programming)?

Well, if you want to write computer programs, this book is for you. This book avoids the snobby of-course-you-already-know assumptions and describes computer programming from scratch.

The book uses Java a powerful, general-purpose computer programming language. But Javas subtleties and eccentricities arent the books main focus. Instead, this book emphasizes a process the process of creating instructions for a computer to follow. Many highfalutin books describe the mechanics of this process the rules, the conventions, and the formalisms. But those other books arent written for real people. Those books dont take you from where you are to where you want to be.

In this book, I assume very little about your experience with computers. As you read each section, you get to see inside my head. You see the problems that I face, the things that I think, and the solutions that I find. Some problems are the kind that I remember facing when I was a novice; other problems are the kind that I face as an expert. I help you understand, I help you visualize, and I help you create solutions on your own. I even get to tell a few funny stories.

I wish I could say, Open to a random page of this book and start writing Java code. Just fill in the blanks and dont look back. In a sense, this is true. You cant break anything by writing Java code, so youre always free to experiment.

But I have to be honest: If you dont understand the bigger picture, writing a program is difficult. Thats true with any computer programming language not just Java. If youre typing code without knowing what its about, and the code doesnt do exactly what you want it to do, youre just plain stuck.

In this book, I divide programming into manageable chunks. Each chunk is (more or less) a chapter. You can jump in anywhere you want , or wherever. You can even start by poking around in the middle of a chapter. Ive tried to make the examples interesting without making one chapter depend on another. When I use an important idea from another chapter, I include a note to help you find your way around.

In general, my advice is as follows:

• If you already know something, dont bother reading about it.
• If youre curious, dont be afraid to skip ahead. You can always sneak a peek at an earlier chapter, if you really need to do so.

Almost every technical book starts with a little typeface legend, and Beginning Programming with Java For Dummies, 5th Edition, is no exception. What follows is a brief explanation of the typefaces used in this book:

• New terms are set in italics.
• When I want you to type something short or perform a step, I use bold.
• Youll also see this computerese font. I use the computerese font for Java code, filenames, web page addresses (URLs), onscreen messages, and other such things. Also, if something you need to type is really long, it appears in computerese font on its own line (or lines).
• You need to change certain things when you type them on your own computer keyboard. For example, I may ask you to type