ALWAYS LEARNING
P
EARSON
Learn more at
www.myprogramminglab.com
My
Programming
Lab™
Through the power of practice and immediate personalized
feedback, MyProgrammingLab improves your performance.
INTRODUCTION TO
JAVA
TM
PROGRAMMING
COMPREHENSIVE VERSION
Ninth Edition
Y. Daniel Liang
Armstrong Atlantic State University
Boston Columbus Indianapolis New York San Francisco Upper Saddle River Amsterdam Cape Town Dubai London Madrid Milan Munich Paris Montreal Toronto
Executive Editor: Tracy Dunkelberger Associate Editor: Carole Snyder Director of Marketing: Patrice Jones Marketing Manager: Yez Alayan Marketing Coordinator: Kathryn Ferranti Marketing Assistant: Emma Snider Director of Production: Vince O’Brien Managing Editor: Jeff Holcomb
Production Project Manager: Kayla Smith-Tarbox Operations Supervisor: Alan Fischer
Manufacturing Buyer: Lisa McDowell
Manager, Visual Research: Karen Sanatar Manager, Rights and Permissions: Mike Joyce Text Permission Coordinator: Danielle Simon
and Jenn Kennett
Cover Illustration: Jason Consalvo Lead Media Project Manager: Daniel Sandin Project Management: Gillian Hall
Composition and Art: Laserwords Printer/Binder: Edwards Brothers
Cover Printer: Lehigh-Phoenix Color/Hagerstown Text Font: Times 10/12
10 9 8 7 6 5 4 3 2 1
ISBN 13: 978-0-13-293652-1 ISBN 10: 0-13-293652-6
Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on the appropriate page within text and as follows: Table 3.2 and 10.1: Data from IRS. Figures 8.1, 8.12, 12.3, 12.5, 12.7, 12.9, 12.10, 12.12–12.21, 12.26–12.30, 13.1, 13.4, 13.9, 13.11, 13.15, 13.17, 13.19, 13.21, 13.23, 13.25–13.35, 14.10, 14.14,15.9–15.11, 16.1, 16.2, 16.8, 16.11, 16.14, 16.17, 16.19–16.35, 17.1, 17.3, 17.6, 17.9, 17.12, 17.13, 17.15, 17.17–17.32, 18.6–18.8, 18.10, 18.15–18.35, 19.19, 19.20, 19.22, 20.1, 20.9, 20.12–20.14, 20.16–20.20, 22.8, 22.17–22.21, 24.4, 24.6, 24.8, 24.11–24.17, 25.18–25.20, 27.17, 27.23-–27.25, 30.10, 30.14, 30.22, 30.23, 30.25, 31.24–31.26, 32.6, 32.7, 32.31–32.34, 33.5, 33.9–33.11, 33.16–33.22, 34.23, 34.27–34.30: Screenshots © 2011 by Oracle Corporation. Reprinted with permission.
Microsoft® and Windows® are registered trademarks of the Microsoft Corporation in the U.S.A. and other coun-tries. Screen shots and icons reprinted with permission from the Microsoft Corporation. This book is not sponsored or endorsed by or affiliated with the Microsoft Corporation.
Copyright © 2013, 2011, 2009, 2007, 2004 by Pearson Education, Inc., publishing as Prentice Hall.All rights reserved. Manufactured in the United States of America. This publication is protected by Copyright, and permis-sion should be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. To obtain permission(s) to use material from this work, please submit a written request to Pearson Education, Inc., Permissions Department, One Lake Street, Upper Saddle River, New Jersey 07458, or you may fax your request to 201-236-3290.
Many of the designations by manufacturers and sellers to distinguish their products are claimed as trademarks. Where those designations appear in this book, and the publisher was aware of a trademark claim, the designations have been printed in initial caps or all caps.
This book is dedicated to Professor Myers Foreman. Myers
used this book in CS1, CS2, and CS3 at Lamar University
and provided invaluable suggestions for improving the book.
Sadly, Myers passed away after he completed the review
of this edition.
PREFACE
Dear Reader,
Many of you have provided feedback on earlier editions of this book, and your comments and suggestions have greatly improved the book. This edition has been substantially enhanced in presentation, organization, examples, exercises, and supplements. We have:
■ Reorganized sections and chapters to present the subjects in a more logical order
■ Included many new interesting examples and exercises to stimulate interests
■ Updated to Java 7
■ Created animations for algorithms and data structures to visually demonstrate the concepts
■ Redesigned the support Website to make it easier to navigate
This book teaches programming in a problem-driven way that focuses on problem solving rather than syntax. We make introductory programming interesting by using thought-provoking problems in a broad context. The central thread of early chapters is on problem solving. Appropriate syntax and library are introduced to enable readers to write programs for solving the problems. To support the teaching of programming in a problem-driven way, the book provides a wide variety of problems at various levels of difficulty to motivate students. To appeal to stu-dents in all majors, the problems cover many application areas, including math, science, business, financial, gaming, animation, and multimedia.
The book focuses on fundamentals first by introducing basic programming concepts and techniques before designing custom classes. The fundamental concepts and techniques of loops, methods, and arrays are the foundation for programming. Building this strong foundation prepares students to learn object-oriented programming and advanced Java programming.
Thiscomprehensive versioncovers fundamentals of programming, object-oriented program-ming, GUI programprogram-ming, algorithms and data structures, concurrency, networking, internation-alization, advanced GUI, database, and Web programming. It is designed to prepare students to become proficient Java programmers. A brief version(Introduction to Java Programming, Brief Version, Ninth Edition) is available for a first course on programming, commonly known as CS1. The brief version contains the first 20 chapters of the comprehensive version.
The best way to teach programming is by example, and the only way to learn programming isby doing. Basic concepts are explained by example, and a large number of exercises with various levels of difficulty are provided for students to practice. For our programming courses, we assign programming exercises after each lecture.
Our goal is to produce a text that teaches problem solving and programming in a broad context using a wide variety of interesting examples. If you have any comments on and suggestions for improving the book, please email me.
Sincerely,
Y. Daniel Liang
[email protected] www.cs.armstrong.edu/liang www.pearsonhighered.com/liang
vii
brief version
comprehensive version fundamentals-first problem-driven what is new?
What’s New in This Edition?
This edition substantially improves Introduction to Java Programming, Eighth Edition. The major improvements are as follows:
■ This edition is completely revised in every detail to enhance clarity, presentation, content, examples, and exercises.
■ New examples and exercises are provided to motivate and stimulate student interest in programming.
■ Each section starts with a Key Point that highlights the important concepts covered in the section.
■ Check Points provide review questions to help students track their progress and evaluate their learning after a major concept or example is covered.
■ Each chapter provides test questions online. They are grouped by sections for students to do self-test. The questions are graded online.
■ New VideoNotes provide short video tutorials designed to reinforce code.
■ The Java GUI API is an excellent example of how the object-oriented principle is applied. Students learn better with concrete and visual examples. So basic GUI/Graphics is moved before introducing abstract classes and interfaces. You can however still choose to cover abstract classes and interfaces before GUI or skip GUI.
■ The numeric wrapper classes, BigInteger, and BigDecimal are now introduced in Chapter 10 to enable students to write code using these classes early.
■ Exception handling is covered before abstract classes and interfaces so that students can build robust programs early. The instructor can still choose to cover exception handling later. Text I/O is now combined with exception handling to form a new chapter.
■ Simple use of generics is introduced along with ArrayListin Chapter 11 and with
Comparable in Chapter 15 while the complex detail on generics is still kept in Chapter 21.
■ Chapter 22 is split into two chapters (Chapter 22 and Chapter 23) to make room for incor-porating three new case studies to demonstrate effective use of data structures.
■ Chapter 24 is expanded to introduce algorithmic techniques: dynamic programming, divide-and-conquer, backtracking, and greedy algorithm with new examples to design efficient algorithms.
■ Visual animations are created to show how data structures and algorithms work.
■ A common problem with a data structures course is lack of good examples and exercises. This edition added many new interesting examples and exercises.
■ Parallel programming techniques are introduced in Chapter 32, Multithreading and Parallel Programming.
■ Chapter 44 is completely new to introduce the latest standard on JSF.
■ Chapter 50 is completely new to introduce testing using JUnit.
Please visit www.cs.armstrong.edu/liang/intro9e/newfeatures.html for a complete list of new features as well as correlations to the previous edition.
new JUnit chapter new JSF chapter parallel programming new data structures materials data structures and algorithm
animation developing efficient
algorithms splitting Chapter 22 simple generics early exception handling earlier numeric classes covered early basic GUI and graphics early test questions
check point key point new problems complete revision
Preface
ix
Pedagogical Features
The book uses the following elements to help students get the most from the material:
■ TheObjectivesat the beginning of each chapter list what students should learn from the chapter. This will help them determine whether they have met the objectives after com-pleting the chapter.
■ TheIntroductionopens the discussion with representative problems to give the reader an overview of what to expect from the chapter.
■ Key Pointshighlight the important concepts covered in each section.
■ Check Pointsprovide review questions to help students track their progress as they read through the chapter and evaluate their learning.
■ Problems and Case Studies, carefully chosen and presented in an easy-to-follow style, teach problem solving and programming concepts. The book uses many small, simple, and stimulating examples to demonstrate important ideas.
■ TheChapter Summaryreviews the important subjects that students should understand and remember. It helps them reinforce the key concepts they have learned in the chapter.
■ Test Questionsare accessible online, grouped by sections, for students to do self-test on programming concepts and techniques.
■ Programming Exercisesare grouped by sections to provide students with opportunities to apply the new skills they have learned on their own. The level of difficulty is rated as easy (no asterisk), moderate (*), hard (**), or challenging (***). The trick of learning programming is practice, practice, and practice. To that end, the book provides a great many exercises.
■ Notes,Tips,Cautions, and Design Guidesare inserted throughout the text to offer valu-able advice and insight on important aspects of program development.
Note
Provides additional information on the subject and reinforces important concepts.
Tip
Teaches good programming style and practice.
Caution
Helps students steer away from the pitfalls of programming errors.
Design Guide
Provides guidelines for designing programs.
Flexible Chapter Orderings
The book is designed to provide flexible chapter orderings to enable GUI, exception handling, recursion, generics, and the Java Collections Framework to be covered earlier or later. The diagram on the next page shows the chapter dependencies.
Organization of the Book
Chapter 45 Web Services Chapter 44 Java Server Faces
Chapter 46 Remote Method Invocation
Chapter 27 Binary Search Trees
Chapter 28 Hashing
Chapter 29 AVL Trees
Chapter 31 Weighted Graphs and Applications
Chapter 30 Graphs and Applications Chapter 23 Sets and Maps
Chapter 24 Developping Efficient Algorithms
Chapter 1 Introduction to Computers, Programs, and Java
Chapter 2 Elementary Programming
Chapter 4 Loops
Chapter 5 Methods
Chapter 7 Multidimensional Arrays
Part I: Fundamentals of Programming
Chapter 3 Selections
Chapter 8 Objects and Classes
Chapter 19 Binary I/O
Note: Chapters 1–20 are in the brief version of this book.
Note: Chapters 1–34 are in the comprehensive version.
Note: Chapters 35–50 are bonus chapters available from the Companion Website.
Chapter 9 Strings
Chapter 10 Thinking in Objects
Chapter 11 Inheritance and Polymorphism
Chapter 14 Exception Handling and Text I/O
Chapter 15 Abstract Classes and Interfaces
Chapter 6 Single-Dimensional Arrays
Part II: Object-Oriented Programming
Chapter 32 Multithreading and Parallel Programming
Chapter 42 Servlets Chapter 33 Networking
Chapter 34 Java Database Programming
Chapter 35 Internationalization
Chapter 41 Advanced Database Programming
Chapter 43 Java Server Pages
Part V: Advanced Java Programming Chapter 12 GUI Basics
Chapter 13 Graphics
Chapter 16 Event-Driven Programming
Chapter 22 Lists, Stacks, Queues, and Priority Queues
Chapter 17 GUI Components
Chapter 18 Applets and Multimedia
Chapter 36 JavaBeans and Bean Events
Chapter 37 Containers, Layout Managers, and Borders
Chapter 38 Menus, Toolbars, and Dialogs
Chapter 39 MVC and Swing Models
Chapter 40 JTable and JTree
Chapter 49 Java 2D
Chapter 50 Testing Using JUnit
Part III: GUI Programming
Chapter 20 Recursion
Ch 6
Chapter 21 Generics
Chapter 26 Implementing Lists, Stacks, Queues, and Priority Queues
Part IV: Data Structures and Algorithms
Ch 8
Ch 15
Ch 18
Chapter 47 2-4 Trees and B- Trees
Chapter 48 Red-Black Trees Chapter 25 Sorting
Pr
ef
for understanding programming and guide students through simple examples and exercises; subsequent chapters progressively present Java programming in detail, culminating with the development of comprehensive Java applications. The appendixes contain a mixed bag of top-ics, including an introduction to number systems and bitwise operations.
Part I: Fundamentals of Programming (Chapters 1–7)
The first part of the book is a stepping stone, preparing you to embark on the journey of learning Java. You will begin to learn about Java (Chapter 1) and fundamental programming techniques with primitive data types, variables, constants, assignments, expressions, and operators (Chapter 2), control statements (Chapters 3–4), methods (Chapter 5), and arrays (Chapters 6–7). After Chapter 6, you can jump to Chapter 20 to learn how to write recursive methods for solving inherently recursive problems.
Part II: Object-Oriented Programming (Chapters 8–11, 14–15, and 19)
This part introduces object-oriented programming. Java is an object-oriented programming language that uses abstraction, encapsulation, inheritance, and polymorphism to provide great flexibility, modularity, and reusability in developing software. You will learn programming with objects and classes (Chapters 8–10), class inheritance (Chapter 11), polymorphism (Chapter 11), exception handling and text I/O (Chapter 14), abstract classes (Chapter 15), and interfaces (Chapter 15). Processing strings is introduced in Chapter 9, and binary I/O is dis-cussed in Chapter 19.
Part III: GUI Programming (Chapters 12–13, 16–18, and Bonus Chapters 36–40 and 49) This part introduces elementary Java GUI programming in Chapters 12–13 and 16–18 and advanced Java GUI programming in Chapters 36–40 and 49. Major topics include GUI basics (Chapter 12), drawing shapes (Chapter 13), event-driven programming (Chapter 16), using GUI components (Chapter 17), and writing applets (Chapter 18). You will learn the architecture of Java GUI programming and use the GUI components to develop applications and applets from these elementary GUI chapters. The advanced GUI chapters discuss Java GUI programming in more depth and breadth. You will delve into JavaBeans and learn how to develop custom events and source components in Chapter 36, review and explore new containers, layout managers, and borders in Chapter 37, learn how to create GUI with menus, popup menus, toolbars, dialogs, and internal frames in Chapter 38, develop components using the MVC approach and explore the advanced Swing components JSpinner,JList, and JComboBoxin Chapter 39, andJTableandJTreein Chapter 40. Chapter 49 introduces Java 2D.
Part IV: Data Structures and Algorithms (Chapters 20–31 and Bonus Chapters 47–48) This part covers the main subjects in a typical data structures course. Chapter 20 introduces recursion to write methods for solving inherently recursive problems. Chapter 21 presents how generics can improve software reliability. Chapters 22 and 23 introduce the Java Collection Framework, which defines a set of useful API for data structures. Chapter 24 dis-cusses measuring algorithm efficiency in order to choose an appropriate algorithm for appli-cations. Chapter 25 describes classic sorting algorithms. You will learn how to implement several classic data structures lists, queues, and priority queues in Chapter 26. Chapters 27 and 29 introduce binary search trees and AVL trees. Chapter 28 presents hashing and imple-menting maps and sets using hashing. Chapters 30 and 31 introduce graph applications. The 2-4 trees, B-trees, and red-black trees are covered in Chapters 47–48.
Part V: Advanced Java Programming (Chapters 32–33 and Bonus Chapters 35, 41–46, and 50)
This part of the book is devoted to advanced Java programming. Chapter 32 treats the use of multithreading to make programs more responsive and interactive and introduces par-allel programming. Chapter 33 discusses how to write programs that talk with each other
over the Internet. Chapter 34 introduces the use of Java to develop database projects, and Chapter 35 covers the use of internationalization support to develop projects for interna-tional audiences. Chapter 41 delves into advanced Java database programming. Bonus Chapters 42, 43 and 44 introduce how to use Java servlets, JavaServer Pages, and JavaServer Faces to generate dynamic content from Web servers. Chapter 45 discusses Web services, and Chapter 46 introduces remote method invocation. Chapter 50 introduces testing Java programs using JUnit.
Appendixes
This part of the book covers a mixed bag of topics. Appendix A lists Java keywords. Appendix B gives tables of ASCII characters and their associated codes in decimal and in hex. Appendix C shows the operator precedence. Appendix D summarizes Java modifiers and their usage. Appendix E discusses special floating-point values. Appendix F introduces num-ber systems and conversions among binary, decimal, and hex numnum-bers. Finally, Appendix G introduces bitwise operations.
Java Development Tools
You can use a text editor, such as the Windows Notepad or WordPad, to create Java programs and to compile and run the programs from the command window. You can also use a Java development tool, such as TextPad, NetBeans, or Eclipse. These tools support an integrated development environment (IDE) for developing Java programs quickly. Editing, compiling, building, executing, and debugging programs are integrated in one graphical user interface. Using these tools effectively can greatly increase your programming productivity. TextPad is a primitive IDE tool. NetBeans and Eclipse are more sophisticated, but they are easy to use if you follow the tutorials. Tutorials on TextPad, NetBeans, and Eclipse can be found in the sup-plements on the Companion Website www.cs.armstrong.edu/liang/intro9e.
Online Practice and Assessment with
MyProgrammingLab
MyProgrammingLab helps students fully grasp the logic, semantics, and syntax of program-ming. Through practice exercises and immediate, personalized feedback, MyProgrammingLab improves the programming competence of beginning students who often struggle with the basic concepts and paradigms of popular high-level programming languages.
A self-study and homework tool, a MyProgrammingLab course consists of hundreds of small practice problems organized around the structure of this textbook. For students, the system automatically detects errors in the logic and syntax of their code submissions and offers targeted hints that enable students to figure out what went wrong—and why. For instructors, a comprehensive gradebook tracks correct and incorrect answers and stores the code inputted by students for review.
MyProgrammingLab is offered to users of this book in partnership with Turing’s Craft, the makers of the CodeLab interactive programming exercise system. For a full demonstration, to see feedback from instructors and students, or to get started using MyProgrammingLab in your course, visit www.myprogramminglab.com.
VideoNotes
We are excited about the new VideoNotes feature that is found in this new edition. These videos provide additional help by presenting examples of key topics and showing how to solve problems completely, from design through coding. VideoNotes are free to first time users and can be accessed by redeeming the access code in the front of this book at www.pearsonhighered.com/liang.
IDE tutorials
LiveLab
This book is accompanied by a complementary Web-based course assessment and manage-ment system for instructors. The system has four main components:
■ TheAutomatic Grading Systemcan automatically grade programs.
■ The Quiz Creation/Submission/Grading System enables instructors to create and modify quizzes that students can take and be graded upon automatically.
■ ThePeer Evaluation Systemenables peer evaluations.
■ Tracking grades, attendance, etc.,lets students track their grades, and enables instruc-tors to view the grades of all students and to track students’ attendance.
The main features of the Automatic Grading System include:
■ Students can run and submit exercises. (The system checks whether their program runs correctly—students can continue to run and resubmit the program before the due date.)
■ Instructors can review submissions, run programs with instructor test cases, correct them, provide feedback to students, and check plagiarism.
■ Instructors can create/modify their own exercises, create public and secret test cases, assign exercises, and set due dates for the whole class or for individuals.
■ Instructors can assign all the exercises in the text to students. Additionally, LiveLab provides extra exercises that are not printed in the text.
■ Instructors can sort and filter all exercises and check grades (by time frame, student, and/or exercise).
■ Instructors can delete students from the system.
■ Students and instructors can track grades on exercises. The main features of the Quiz System are:
■ Instructors can create/modify quizzes from the test bank or a text file or create completely new tests online.
■ Instructors can assign the quizzes to students and set a due date and test time limit for the whole class or for individuals.
■ Students and instructors can review submitted quizzes.
■ Instructors can analyze quizzes and identify students’ weaknesses.
■ Students and instructors can track grades on quizzes. The main features of the Peer Evaluation System include:
■ Instructors can assign peer evaluation for programming exercises.
■ Instructors can view peer evaluation reports.
Student Resource Website
The Student Resource Website (www.cs.armstrong.edu/liang/intro9e) contains the following resources:
■ Access to VideoNotes (www.pearsonhighered.com/liang).
■ Answers to check point questions
■ Solutions to even-numbered programming exercises
■ Source code for the examples in the book
■ Interactive self-testing (organized by sections for each chapter)
■ Data structures and algorithm animations
■ Errata
Instructor Resource Website
The Instructor Resource Website, accessible from www.cs.armstrong.edu/liang/intro9e, contains the following resources:
■ Microsoft PowerPoint slides with interactive buttons to view full-color, syntax-highlighted source code and to run programs without leaving the slides.
■ Solutions to all programming exercises. Students will have access to the solutions of even-numbered programming exercises.
■ Web-based quiz generator. (Instructors can choose chapters to generate quizzes from a large database of more than two thousand questions.)
■ Sample exams. Most exams have four parts:
■ Multiple-choice questions or short-answer questions
■ Correct programming errors
■ Trace programs
■ Write programs
■ Projects. In general, each project gives a description and asks students to analyze, design, and implement the project.
Some readers have requested the materials from the Instructor Resource Website. Please understand that these are for instructors only. Such requests will not be answered.
Algorithm Animations
We have provided numerous animations for algorithms. These are valuable pedagogical tools to demonstrate how algorithms work. Algorithm animations can be accessed from the Companion Website.
Acknowledgments
I would like to thank Armstrong Atlantic State University for enabling me to teach what I write and for supporting me in writing what I teach. Teaching is the source of inspiration for continuing to improve the book. I am grateful to the instructors and students who have offered comments, suggestions, bug reports, and praise.
Engel (New York University), Henry A. Etlinger (Rochester Institute of Technology), James Ten Eyck (Marist College), Myers Foreman (Lamar University), Olac Fuentes (University of Texas at El Paso), Edward F. Gehringer (North Carolina State University), Harold Grossman (Clemson University), Barbara Guillot (Louisiana State University), Stuart Hansen (University of Wisconsin, Parkside), Dan Harvey (Southern Oregon University), Ron Hofman (Red River College, Canada), Stephen Hughes (Roanoke College), Vladan Jovanovic (Georgia Southern University), Edwin Kay (Lehigh University), Larry King (University of Texas at Dallas), Nana Kofi (Langara College, Canada), George Koutsogiannakis (Illinois Institute of Technology), Roger Kraft (Purdue University at Calumet), Norman Krumpe (Miami University), Hong Lin (DeVry Institute), Dan Lipsa (Armstrong Atlantic State University), James Madison (Rensselaer Polytechnic Institute), Frank Malinowski (Darton College), Tim Margush (University of Akron), Debbie Masada (Sun Microsystems), Blayne Mayfield (Oklahoma State University), John McGrath (J.P. McGrath Consulting), Hugh McGuire (Grand Valley State), Shyamal Mitra (University of Texas at Austin), Michel Mitri (James Madison University), Kenrick Mock (University of Alaska Anchorage), Frank Murgolo (California State University, Long Beach), Jun Ni (University of Iowa), Benjamin Nystuen (University of Colorado at Colorado Springs), Maureen Opkins (CA State University, Long Beach), Gavin Osborne (University of Saskatchewan), Kevin Parker (Idaho State University), Dale Parson (Kutztown University), Mark Pendergast (Florida Gulf Coast University), Richard Povinelli (Marquette University), Roger Priebe (University of Texas at Austin), Mary Ann Pumphrey (De Anza Junior College), Pat Roth (Southern Polytechnic State University), Amr Sabry (Indiana University), Carolyn Schauble (Colorado State University), David Scuse (University of Manitoba), Ashraf Shirani (San Jose State University), Daniel Spiegel (Kutztown University), Joslyn A. Smith (Florida Atlantic University) , Lixin Tao (Pace University), Ronald F. Taylor (Wright State University), Russ Tront (Simon Fraser University), Deborah Trytten (University of Oklahoma), Kent Vidrine (George Washington University), and Bahram Zartoshty (California State University at Northridge).
It is a great pleasure, honor, and privilege to work with Pearson. I would like to thank Tracy Dunkelberger and her colleagues Marcia Horton, Michael Hirsch, Matt Goldstein, Carole Snyder, Tim Huddleston, Yez Alayan, Jeff Holcomb, Kayla Smith-Tarbox, Gillian Hall, Rebecca Greenberg, and their colleagues for organizing, producing, and promoting this project.
As always, I am indebted to my wife, Samantha, for her love, support, and encouragement.
BRIEF CONTENTS
1
Introduction to Computers, Programs,and Java 1
2
Elementary Programming 333
Selections 814
Loops 1335
Methods 1776
Single-Dimensional Arrays 2237
Multidimensional Arrays 2638
Objects and Classes 2959
Strings 33510
Thinking in Objects 36911
Inheritance and Polymorphism 40712
GUI Basics 44513
Graphics 47914
Exception Handling and Text I/O 51715
Abstract Classes and Interfaces 55916
Event-Driven Programming 59917
GUI Components 63918
Applets and Multimedia 67119
Binary I/O 70920
Recursion 73721
Generics 76922
Lists, Stacks, Queues, and PriorityQueues 793
23
Sets and Maps 82924
Developing Efficient Algorithms 85325
Sorting 89326
Implementing Lists, Stacks, Queues,and Priority Queues 927
27
Binary Search Trees 96128
Hashing 99729
AVL Trees 102730
Graphs and Applications 104731
Weighted Graphs and Applications 109332
Multithreading and ParallelProgramming 1129
33
Networking 117534
Java Database Programming 1211Chapters 35–50 are bonus Web chapters
35
Internationalization 35-136
JavaBeans 36-137
Containers, Layout Managers,and Borders 37-1
38
Menus, Toolbars, and Dialogs 38-139
MVC and Swing Models 39-140
JTable and JTree 40-141
Advanced Database Programming 41-142
Servlets 42-143
JavaServer Pages 43-144
JavaServer Faces 44-145
Web Services 45-146
Remote Method Invocation 46-147
2-4 Trees and B-Trees 47-148
Red-Black Trees 48-149
Java 2D 49-150
Testing Using JUnit 50-1A
PPENDIXESA
Java Keywords 1251B
The ASCII Character Set 1254C
Operator Precedence Chart 1256D
Java Modifiers 1258E
Special Floating-Point Values 1260F
Number Systems 1261G
Bitwise Operatoirns 1265I
NDEX 1267CONTENTS
Chapter 1
Introduction to Computers, Programs,
and Java
11.1 Introduction 2
1.2 What Is a Computer? 2
1.3 Programming Languages 9
1.4 Operating Systems 12
1.5 Java, the World Wide Web, and Beyond 13
1.6 The Java Language Specification, API, JDK, and IDE 16
1.7 A Simple Java Program 16
1.8 Creating, Compiling, and Executing a Java Program 19
1.9 Displaying Text in a Message Dialog Box 22
1.10 Programming Style and Documentation 24
1.11 Programming Errors 26
Chapter 2
Elementary Programming
332.1 Introduction 34
2.2 Writing a Simple Program 34
2.3 Reading Input from the Console 37
2.4 Identifiers 40
2.5 Variables 40
2.6 Assignment Statements and Assignment Expressions 42
2.7 Named Constants 43
2.8 Naming Conventions 44
2.9 Numeric Data Types and Operations 44
2.10 Numeric Literals 48
2.11 Evaluating Expressions and Operator Precedence 50
2.12 Case Study: Displaying the Current Time 51
2.13 Augmented Assignment Operators 53
2.14 Increment and Decrement Operators 54
2.15 Numeric Type Conversions 56
2.16 Software Development Process 58
2.17 Character Data Type and Operations 62
2.18 The StringType 68
2.19 Getting Input from Input Dialogs 70
Chapter 3
Selections
813.1 Introduction 82
3.2 booleanData Type 82
3.3 ifStatements 84
3.4 Case Study: Guessing Birthdays 86
3.5 Two-Way if-elseStatements 89
3.6 Nested ifand Multi-Way if-elseStatements 91
3.7 Common Errors in Selection Statements 93
3.8 Generating Random Numbers 96
3.9 Case Study: Computing Body Mass Index 97
3.10 Case Study: Computing Taxes 99
3.11 Logical Operators 101
3.12 Case Study: Determining Leap Year 105
3.13 Case Study: Lottery 106
3.14 switchStatements 108
3.15 Conditional Expressions 111
3.16 Formatting Console Output 112
3.17 Operator Precedence and Associativity 115
3.18 Confirmation Dialogs 117
3.19 Debugging 119
Chapter 4
Loops
1334.1 Introduction 134
4.2 The whileLoop 134
4.3 The do-whileLoop 144
4.4 The forLoop 146
4.5 Which Loop to Use? 150
4.6 Nested Loops 152
4.7 Minimizing Numeric Errors 154
4.8 Case Studies 155
4.9 Keywords breakandcontinue 159
4.10 Case Study: Displaying Prime Numbers 162
4.11 Controlling a Loop with a Confirmation Dialog 164
Chapter 5
Methods
1775.1 Introduction 178
5.2 Defining a Method 178
5.3 Calling a Method 180
5.4 voidMethod Example 183
5.5 Passing Parameters by Values 186
5.6 Modularizing Code 189
5.7 Case Study: Converting Decimals to Hexadecimals 191
5.8 Overloading Methods 193
5.9 The Scope of Variables 196
5.11 Case Study: Generating Random Characters 201
5.12 Method Abstraction and Stepwise Refinement 203
Chapter 6
Single-Dimensional Arrays
2236.1 Introduction 224
6.2 Array Basics 224
6.3 Case Study: Lotto Numbers 231
6.4 Case Study: Deck of Cards 234
6.5 Copying Arrays 236
6.6 Passing Arrays to Methods 237
6.7 Returning an Array from a Method 240
6.8 Case Study: Counting the Occurrences of Each Letter 241
6.9 Variable-Length Argument Lists 244
6.10 Searching Arrays 245
6.11 Sorting Arrays 248
6.12 The ArraysClass 252
Chapter 7
Multidimensional Arrays
2637.1 Introduction 264
7.2 Two-Dimensional Array Basics 264
7.3 Processing Two-Dimensional Arrays 267
7.4 Passing Two-Dimensional Arrays to Methods 269
7.5 Case Study: Grading a Multiple-Choice Test 270
7.6 Case Study: Finding the Closest Pair 272
7.7 Case Study: Sudoku 274
7.8 Multidimensional Arrays 277
Chapter 8
Objects and Classes
2958.1 Introduction 296
8.2 Defining Classes for Objects 296
8.3 Example: Defining Classes and Creating Objects 298
8.4 Constructing Objects Using Constructors 303
8.5 Accessing Objects via Reference Variables 304
8.6 Using Classes from the Java Library 308
8.7 Static Variables, Constants, and Methods 312
8.8 Visibility Modifiers 317
8.9 Data Field Encapsulation 319
8.10 Passing Objects to Methods 322
8.11 Array of Objects 326
Chapter 9
Strings
3359.1 Introduction 336
9.2 The StringClass 336
9.3 Case Study: Checking Palindromes 347
9.4 Case Study: Converting Hexadecimals to Decimals 348
9.5 The CharacterClass 350
9.6 The StringBuilderandStringBuffer 353
9.7 Command-Line Arguments 358
Chapter 10
Thinking in Objects
36910.1 Introduction 370
10.2 Immutable Objects and Classes 370
10.3 The Scope of Variables 371
10.4 The thisReference 373
10.5 Class Abstraction and Encapsulation 375
10.6 Object-Oriented Thinking 379
10.7 Object Composition 382
10.8 Case Study: Designing the CourseClass 384
10.9 Case Study: Designing a Class for Stacks 386
10.10 Case Study: Designing the GuessDateClass 388
10.11 Class Design Guidelines 391
10.12 Processing Primitive Data Type Values as Objects 393
10.13 Automatic Conversion between Primitive Types
and Wrapper Class Types 396
10.14 The BigIntegerandBigDecimal 397
Chapter 11
Inheritance and Polymorphism
40711.1 Introduction 408
11.2 Superclasses and Subclasses 408
11.3 Using the superKeyword 414
11.4 Overriding Methods 418
11.5 Overriding vs. Overloading 418
11.6 The ObjectClass and Its toString() 420
11.7 Polymorphism 421
11.8 Dynamic Binding 422
11.9 Casting Objects and the instanceofOperator 425
11.10 The Object’s equalsmethod 429
11.11 The ArrayListClass 430
11.12 Case Study: A Custom Stack Class 436
11.13 The protectedData and Methods 437
11.14 Preventing Extending and Overriding 439
Chapter 12
GUI Basics
44512.1 Introduction 446
12.3 The Java GUI API 446
12.4 Frames 449
12.5 Layout Managers 451
12.6 Using Panels as Subcontainers 458
12.7 The ColorClass 460
12.8 The FontClass 461
12.9 Common Features of Swing GUI Components 462
12.10 Image Icons 465
12.11 JButton 467
12.12 JCheckBox 471
12.13 JRadioButton 472
12.14 Labels 473
12.15 Text Fields 474
Chapter 13
Graphics
47913.1 Introduction 480
13.2 The GraphicsClass 480
13.3 Drawing Strings, Lines, Rectangles, and Ovals 483
13.4 Case Study: The FigurePanelClass 485
13.5 Drawing Arcs 488
13.6 Drawing Polygons and Polylines 490
13.7 Centering a String Using the FontMetricsClass 493
13.8 Case Study: The MessagePanelClass 495
13.9 Case Study: The StillClockClass 500
13.10 Displaying Images 504
13.11 Case Study: The ImageViewerClass 506
Chapter 14
Exception Handling and Text I/O
51714.1 Introduction 518
14.2 Exception-Handling Overview 518
14.3 Exception Types 523
14.4 More on Exception Handling 526
14.5 The finallyClause 534
14.6 When to Use Exceptions 535
14.7 Rethrowing Exceptions 536
14.8 Chained Exceptions 537
14.9 Defining Custom Exception Classes 538
14.10 The FileClass 541
14.11 File Input and Output 544
14.12 File Dialogs 549
14.13 Reading Data from the Web 551
Chapter 15
Abstract Classes and Interfaces
55915.1 Introduction 560
15.2 Abstract Classes 560
15.3 Case Study: the Abstract NumberClass 565
15.4 Case Study: CalendarandGregorianCalendar 567
15.5 Interfaces 570
15.6 The ComparableInterface 573
15.7 The Cloneable Interface 577
15.8 Interfaces vs. Abstract Classes 581
15.9 Case Study: The RationalClass 584
Chapter 16
Event-Driven Programming
59916.1 Introduction 600
16.2 Events and Event Sources 602
16.3 Listeners, Registrations, and Handling Events 603
16.4 Inner Classes 608
16.5 Anonymous Class Listeners 609
16.6 Alternative Ways of Defining Listener Classes 612
16.7 Case Study: Loan Calculator 615
16.8 Mouse Events 617
16.9 Listener Interface Adapters 620
16.10 Key Events 621
16.11 Animation Using the TimerClass 625
Chapter 17
GUI Components
63917.1 Introduction 640
17.2 Events for JCheckBox, JRadioButtonandJTextField 640
17.3 Text Areas 644
17.4 Combo Boxes 647
17.5 Lists 650
17.6 Scroll Bars 654
17.7 Sliders 657
17.8 Creating Multiple Windows 660
Chapter 18
Applets and Multimedia
67118.1 Introduction 672
18.2 Developing Applets 672
18.3 The HTML File and the <applet>Tag 673
18.5 Enabling Applets to Run as Applications 676
18.6 Applet Life-Cycle Methods 677
18.7 Passing Strings to Applets 679
18.8 Case Study: Bouncing Ball 683
18.9 Case Study: Developing a Tic-Tac-Toe Game 686
18.10 Locating Resources Using the URLClass 691
18.11 Playing Audio in Any Java Program 693
18.12 Case Study: National Flags and Anthems 695
Chapter 19
Binary I/O
70919.1 Introduction 710
19.2 How Is Text I/O Handled in Java? 710
19.3 Text I/O vs. Binary I/O 711
19.4 Binary I/O Classes 712
19.5 Case Study: Copying Files 722
19.6 Object I/O 724
19.7 Random-Access Files 729
Chapter 20
Recursion
73720.1 Introduction 738
20.2 Case Study: Computing Factorials 738
20.3 Case Study: Computing Fibonacci Numbers 741
20.4 Problem Solving Using Recursion 744
20.5 Recursive Helper Methods 746
20.6 Case Study: Finding the Directory Size 749
20.7 Case Study: Towers of Hanoi 750
20.8 Case Study: Fractals 754
20.9 Recursion vs. Iteration 757
20.10 Tail Recursion 758
Chapter 21
Generics
76921.1 Introduction 770
21.2 Motivations and Benefits 770
21.3 Defining Generic Classes and Interfaces 772
21.4 Generic Methods 774
21.5 Case Study: Sorting an Array of Objects 776
21.6 Raw Types and Backward Compatibility 778
21.7 Wildcard Generic Types 779
21.8 Erasure and Restrictions on Generics 782
21.9 Case Study: Generic Matrix Class 784
Chapter 22
Lists, Stacks, Queues, and
Priority Queues
79322.1 Introduction 794
22.2 Collections 794
22.3 Iterators 798
22.4 Lists 799
22.5 The ComparatorInterface 803
22.6 Static Methods for Lists and Collections 805
22.7 Case Study: Bouncing Balls 809
22.8 The VectorandStackClasses 813
22.9 Queues and Priority Queues 814
22.10 Case Study: Evaluating Expressions 817
Chapter 23
Sets and Maps
82923.1 Introduction 830
23.2 Sets 830
23.3 Comparing the Performance of Sets and Lists 838
23.4 Case Study: Counting Keywords 841
23.5 Maps 842
23.6 Case Study: Occurrences of Words 847
23.7 Singleton and Unmodifiable Collections and Maps 848
Chapter 24
Developing Efficient Algorithms
85324.1 Introduction 854
24.2 Measuring Algorithm Efficiency Using Big ONotation 854
24.3 Examples: Determining Big O 856
24.4 Analyzing Algorithm Time Complexity 859
24.5 Finding Fibonacci Numbers Using Dynamic Programming 862
24.6 Finding Greatest Common Divisors Using Euclid’s Algorithm 864
24.7 Efficient Algorithms for Finding Prime Numbers 869
24.8 Finding the Closest Pair of Points Using Divide-and-Conquer 875
24.9 Solving the Eight Queens Problem Using Backtracking 877
24.10 Computational Geometry: Finding a Convex Hull 880
Chapter 25
Sorting
89325.1 Introduction 894
25.2 Bubble Sort 894
25.3 Merge Sort 896
25.4 Quick Sort 900
25.5 Heap Sort 904
25.6 Bucket Sort and Radix Sort 911
Chapter 26
Implementing Lists, Stacks, Queues,
and Priority Queues
92726.1 Introduction 928
26.2 Common Features for Lists 928
26.3 Array Lists 932
26.4 Linked Lists 938
26.5 Stacks and Queues 952
26.6 Priority Queues 955
Chapter 27
Binary Search Trees
96127.1 Introduction 962
27.2 Binary Search Trees 962
27.3 Deleting Elements from a BST 975
27.4 Tree Visualization 981
27.5 Iterators 984
27.6 Case Study: Data Compression 986
Chapter 28
Hashing
99728.1 Introduction 998
28.2 What Is Hashing? 998
28.3 Hash Functions and Hash Codes 999
28.4 Handling Collisions Using Open Addressing 1001
28.5 Handling Collisions Using Separate Chaining 1005
28.6 Load Factor and Rehashing 1005
28.7 Implementing a Map Using Hashing 1007
28.8 Implementing Set Using Hashing 1016
Chapter 29
AVL Trees
102729.1 Introduction 1028
29.2 Rebalancing Trees 1028
29.3 Designing Classes for AVL Trees 1031
29.4 Overriding the insertMethod 1032
29.5 Implementing Rotations 1033
29.6 Implementing the deleteMethod 1034
29.7 The AVLTreeClass 1034
29.8 Testing the AVLTreeClass 1040
29.9 AVL Tree Time Complexity Analysis 1043
Chapter 30
Graphs and Applications
104730.1 Introduction 1048
30.2 Basic Graph Terminologies 1049
30.3 Representing Graphs 1051
30.4 Modeling Graphs 1056
30.5 Graph Visualization 1066
30.6 Graph Traversals 1069
30.7 Depth-First Search (DFS) 1070
30.8 Case Study: The Connected Circles Problem 1074
30.9 Breadth-First Search (BFS) 1077
30.10 Case Study: The Nine Tails Problem 1080
Chapter 31
Weighted Graphs and Applications
109331.1 Introduction 1094
31.2 Representing Weighted Graphs 1095
31.3 The WeightedGraphClass 1097
31.4 Minimum Spanning Trees 1105
31.5 Finding Shortest Paths 1111
31.6 Case Study: The Weighted Nine Tails Problem 1119
Chapter 32
Multithreading and Parallel
Programming
112932.1 Introduction 1130
32.2 Thread Concepts 1130
32.3 Creating Tasks and Threads 1130
32.4 The ThreadClass 1134
32.5 Case Study: Flashing Text 1137
32.6 GUI Event Dispatch Thread 1138
32.7 Case Study: Clock with Audio 1139
32.8 Thread Pools 1142
32.9 Thread Synchronization 1144
32.10 Synchronization Using Locks 1148
32.11 Cooperation among Threads 1150
32.12 Case Study: Producer/Consumer 1155
32.13 Blocking Queues 1158
32.14 Semaphores 1160
32.15 Avoiding Deadlocks 1162
32.16 Thread States 1163
32.17 Synchronized Collections 1163
32.18 Parallel Programming 1165
Chapter 33
Networking
117533.1 Introduction 1176
Contents
xxvii
33.3 The InetAddressClass 1183
33.4 Serving Multiple Clients 1184
33.5 Applet Clients 1187
33.6 Sending and Receiving Objects 1190
33.7 Case Study: Distributed Tic-Tac-Toe Games 1195
Chapter 34
Java Database Programming
121134.1 Introduction 1212
34.2 Relational Database Systems 1212
34.3 SQL 1216
34.4 JDBC 1227
34.5 PreparedStatement 1235
34.6 CallableStatement 1238
34.7 Retrieving Metadata 1241
Bonus Chapters 35–50 are available from the companion Website at
www.pearsonhighered.com/liang:
Chapter 35
Internationalization
35-1Chapter 36
JavaBeans
36-1Chapter 37
Containers, Layout Managers,
and Borders
37-1Chapter 38
Menus, Toolbars, and Dialogs
38-1Chapter 39
MVC and Swing Models
39-1Chapter 40
JTable and JTree
40-1Chapter 41
Advanced Database Programming
41-1Chapter 42
Servlets
42-1Chapter 43
JavaServer Pages
43-1Chapter 44
JavaServer Faces
44-1Chapter 45
Web Services
45-1Chapter 47
2-4 Trees and B-Trees
47-1Chapter 48
Red-Black Trees
48-1Chapter 49
Java 2D
49-1Chapter 50
Testing Using JUnit
50-1A
PPENDIXES
Appendix A
Java Keywords 1251Appendix B
The ASCII Character Set 1254Appendix C
Operator Precedence Chart 1256Appendix D
Java Modifiers 1258Appendix E
Special Floating-Point Values 1260Appendix F
Number Systems 1261Appendix G
Bitwise Operations 1265VideoNotes
Locations of VideoNotes
http://www.pearsonhighered.com/liang
Chapter 1 Introduction to Computers, Programs, and Java
Your first Java program 17
Eclipse brief tutorial 19
NetBeans brief tutorial 19 Compile and run a Java program 21
Chapter 2 Elementary Programming
Obtain input 37
Use operators / and % 51
Software development process 58
Compute loan payments 59
Compute BMI 77
Chapter 3 Selections
Program addition quiz 83
Program subtraction quiz 96 Use multi-way if-elsestatements 99
Sort three integers 123
Check point location 125
Chapter 4 Loops
Guess a number 137
Multiple subtraction quiz 139 Minimize numeric errors 154
Display loan schedule 170
Sum a series 170
Chapter 5 Methods
Define/invoke maxmethod 180
Usevoidmethod 183
Modularize code 189
Stepwise refinement 203
Reverse an integer 212
Estimate 215
Chapter 6 Single-Dimensional Arrays
Random shuffling 228
Lotto numbers 231
Selection sort 249
Coupon collector’s problem 260
Consecutive four 261
Chapter 7 Multidimensional Arrays
Find the row with the largest sum 268 Grade multiple-choice test 270
Sudoku 274
Multiply two matrices 282
Even number of 1s 289
Chapter 8 Objects and Classes
Define classes and objects 296
Use classes 311
Static vs. instance 312
Data field encapsulation 319
TheFanclass 331
p
VideoNote
Chapter 9 Strings
Check palindrome 347
Command-line argument 359
Number conversion 364
Check ISBN-10 367
Chapter 10 Thinking in Objects
Immutable objects and thiskeyword 370
TheLoanclass 376
The BMI class 380
TheStackOfIntegersclass 386
Process large numbers 397
TheMyPointclass 400
Chapter 11 Inheritance and Polymorphism
Geometric class hierarchy 408 Polymorphism and dynamic binding demo 423
TheArrayListclass 430
TheMyStackclass 436
New Accountclass 443
Chapter 12 GUI Basics
UseFlowLayout 452
Use panels as subcontainers 458 Use Swing common properties 462 Display a checkerboard 477 Display a random matrix 478
Chapter 13 Graphics
TheFigurePanelclass 485
TheMessagePanelclass 495
TheStillClockclass 500
Plot a function 511
Plot a bar chart 512
Chapter 14 Exception Handling and Text I/O
Exception-handling advantages 518 Create custom exception classes 538
Write and read data 544
HexFormatException 555
Chapter 15 Abstract Classes and Interfaces
Abstract GeometricObjectclass 560
CalendarandGregorianCalendarclasses 567 The concept of interface 570 Redesign the Rectangleclass 593
Chapter 16 Event-Driven Programming
Listener and its registration 607
Anonymous listener 610
Move message using the mouse 618
Animate a clock 628
Animate a rising flag 632
Check mouse point location 632
Chapter 17 GUI Components
Use text areas 668
Chapter 18 Applets and Multimedia
First applet 672
Run applets standalone 676
VideoNotes
xxxi
Audio and image 695
Control a group of clocks 701
Chapter 19 Binary I/O
Copy file 722
Object I/O 724
Split a large file 734
Chapter 20 Recursion
Binary search 748
Directory size 749
I
NTRODUCTION
TO
C
OMPUTERS
,
P
ROGRAMS
,
AND
J
AVA
Objectives
■ To understand computer basics, programs, and operating systems (§§1.2–1.4).
■ To describe the relationship between Java and the World Wide Web (§1.5).
■ To understand the meaning of Java language specification, API, JDK, and IDE (§1.6).
■ To write a simple Java program (§1.7).
■ To display output on the console (§1.7).
■ To explain the basic syntax of a Java program (§1.7).
■ To create, compile, and run Java programs (§1.8).
■ To display output using the JOptionPanemessage dialog boxes (§1.9).
■ To become familiar with Java programming style and documenta-tion (§1.10).
■ To explain the differences between syntax errors, runtime errors, and logic errors (§1.11).
CHAPTER
1.1 Introduction
The central theme of this book is to learn how to solve problems by writing a program.
This book is about programming. So, what is programming? The term programmingmeans to create (or develop) software, which is also called a program.In basic terms, software contains the instructions that tell a computer—or a computerized device—what to do.
Software is all around you, even in devices that you might not think would need it. Of course, you expect to find and use software on a personal computer, but software also plays a role in running airplanes, cars, cell phones, and even toasters. On a personal computer, you use word processors to write documents, Web browsers to explore the Internet, and e-mail programs to send messages. These programs are all examples of software. Software develop-ers create software with the help of powerful tools called programming languages.
This book teaches you how to create programs by using the Java programming language. There are many programming languages, some of which are decades old. Each language was invented for a specific purpose—to build on the strengths of a previous language, for exam-ple, or to give the programmer a new and unique set of tools. Knowing that there are so many programming languages available, it would be natural for you to wonder which one is best. But, in truth, there is no “best” language. Each one has its own strengths and weaknesses. Experienced programmers know that one language might work well in some situations, whereas a different language may be more appropriate in other situations. For this reason, seasoned programmers try to master as many different programming languages as they can, giving them access to a vast arsenal of software-development tools.
If you learn to program using one language, you should find it easy to pick up other lan-guages. The key is to learn how to solve problems using a programming approach. That is the main theme of this book.
You are about to begin an exciting journey: learning how to program. At the outset, it is helpful to review computer basics, programs, and operating systems. If you are already famil-iar with such terms as CPU, memory, disks, operating systems, and programming languages, you may skip the review in Sections 1.2–1.4.
1.2 What Is a Computer?
A computer is an electronic device that stores and processes data.
A computer includes both hardwareandsoftware.In general, hardware comprises the visible, physical elements of the computer, and software provides the invisible instructions that con-trol the hardware and make it perform specific tasks. Knowing computer hardware isn’t essential to learning a programming language, but it can help you better understand the effects that a program’s instructions have on the computer and its components. This section intro-duces computer hardware components and their functions.
A computer consists of the following major hardware components (Figure 1.1):
■ A central processing unit (CPU)
■ Memory (main memory)
■ Storage devices (such as disks and CDs)
■ Input devices (such as the mouse and keyboard)
■ Output devices (such as monitors and printers)
■ Communication devices (such as modems and network interface cards)
A computer’s components are interconnected by a subsystem called a bus.You can think of a bus as a sort of system of roads running among the computer’s components; data and
what is programming? programming program
hardware software
bus
Key Point
1.2 What Is a Computer?
3
CPU
Bus
Memory
Storage Devices
Input Devices
Output Devices
Communication Devices
FIGURE1.1 A computer consists of a CPU, memory, storage devices, input devices, output devices, and communication devices.
motherboard
power travel along the bus from one part of the computer to another. In personal computers, the bus is built into the computer’s motherboard,which is a circuit case that connects all of the parts of a computer together, as shown in Figure 1.2.
1.2.1
Central Processing Unit
The central processing unit (CPU) is the computer’s brain. It retrieves instructions from memory and executes them. The CPU usually has two components: a control unit and an
arithmetic/logic unit.The control unit controls and coordinates the actions of the other com-ponents. The arithmetic/logic unit performs numeric operations (addition, subtraction, multi-plication, division) and logical operations (comparisons).
Today’s CPUs are built on small silicon semiconductor chips that contain millions of tiny electric switches, called transistors,for processing information.
Every computer has an internal clock, which emits electronic pulses at a constant rate. These pulses are used to control and synchronize the pace of operations. A higher clock speed
enables more instructions to be executed in a given period of time. The unit of measurement of clock speed is the hertz(Hz), with 1 hertz equaling 1 pulse per second. In the 1990s computers measured clocked speed in megahertz(MHz), but CPU speed has been improving continuously,
CPU
speed
and the clock speed of a computer is now usually stated in gigahertz (GHz).Intel’s newest processors run at about 3 GHz.
CPUs were originally developed with only one core. The coreis the part of the processor that performs the reading and executing of instructions. In order to increase CPU processing power, chip manufacturers are now producing CPUs that contain multiple cores. A multicore CPU is a single component with two or more independent processors. Today’s consumer computers typically have two, three, and even four separate cores. Soon, CPUs with dozens or even hundreds of cores will be affordable.
1.2.2
Bits and Bytes
Before we discuss memory, let’s look at how information (data and programs) are stored in a computer.
A computer is really nothing more than a series of switches. Each switch exists in two states: on or off. Storing information in a computer is simply a matter of setting a sequence of switches on or off. If the switch is on, its value is 1. If the switch is off, its value is 0. These 0s and 1s are interpreted as digits in the binary number system and are called bits
(binary digits).
The minimum storage unit in a computer is a byte.A byte is composed of eight bits. A small number such as 3can be stored as a single byte. To store a number that cannot fit into a single byte, the computer uses several bytes.
Data of various kinds, such as numbers and characters, are encoded as a series of bytes. As a programmer, you don’t need to worry about the encoding and decoding of data, which the computer system performs automatically, based on the encoding scheme. An encoding schemeis a set of rules that govern how a computer translates characters, numbers, and sym-bols into data the computer can actually work with. Most schemes translate each character into a predetermined string of numbers. In the popular ASCII encoding scheme, for example, the character Cis represented as 01000011in one byte.
bits
byte
encoding scheme
CPU is placed under the fan
Memory
Motherboard
FIGURE1.2 The motherboard connects all parts of a computer together.
gigahertz
1.2 What Is a Computer?
5
01000011 01110010 01100101 01110111 00000011
Encoding for character ‘C’ Encoding for character ‘r’ Encoding for character ‘e’ Encoding for character ‘w’ Encoding for number 3 2000
2001 2002 2003 2004
Memory address Memory content
FIGURE1.3 Memory stores data and program instructions in uniquely addressed memory locations. Each memory location can store one byte of data.
A computer’s storage capacity is measured in bytes and multiples of the byte, as follows:
■ Akilobyte (KB)is about 1,000 bytes.
■ Amegabyte (MB)is about 1 million bytes.
■ Agigabyte (GB)is about 1 billion bytes.
■ Aterabyte (TB)is about 1 trillion bytes.
A typical one-page word document might take 20 KB. Therefore, 1 MB can store 50 pages of documents and 1 GB can store 50,000 pages of documents. A typical two-hour high-resolution movie might take 8 GB, so it would require 160 GB to store 20 movies.
1.2.3
Memory
A computer’s memoryconsists of an ordered sequence of bytes for storing programs as well as data that the program is working with. You can think of memory as the computer’s work area for executing a program. A program and its data must be moved into the computer’s memory before they can be executed by the CPU.
Every byte in the memory has a unique address, as shown in Figure 1.3. The address is used to locate the byte for storing and retrieving the data. Since the bytes in the memory can be accessed in any order, the memory is also referred to as random-access memory (RAM).
Today’s personal computers usually have at least 1 gigabyte of RAM, but they more com-monly have 2 to 4 GB installed. Generally speaking, the more RAM a computer has, the faster it can operate, but there are limits to this simple rule of thumb.
A memory byte is never empty, but its initial content may be meaningless to your program. The current content of a memory byte is lost whenever new information is placed in it.
Like the CPU, memory is built on silicon semiconductor chips that have millions of tran-sistors embedded on their surface. Compared to CPU chips, memory chips are less compli-cated, slower, and less expensive.
1.2.4
Storage Devices
A computer’s memory (RAM) is a volatile form of data storage: any information that has been stored in memory (that is, saved) is lost when the system’s power is turned off. Programs and data are permanently stored on storage devicesand are moved, when the computer actually uses them, to memory, which operates at much faster speeds than permanent storage devices can.
kilobyte (KB)
megabyte (MB)
gigabyte (GB)
terabyte (TB)
memory
unique address
RAM
FIGURE1.4 A hard disk is a device for permanently storing programs and data. There are three main types of storage devices:
■ Magnetic disk drives
■ Optical disc drives (CD and DVD)
■ USB flash drives
Drivesare devices for operating a medium, such as disks and CDs. A storage medium physically stores data and program instructions. The drive reads data from the medium and writes data onto the medium.
Disks
A computer usually has at least one hard disk drive (Figure 1.4). Hard disksare used for per-manently storing data and programs. Newer computers have hard disks that can store from 200 to 800 gigabytes of data. Hard disk drives are usually encased inside the computer, but removable hard disks are also available.
CDs and DVDs
CDstands for compact disc. There are two types of CD drives: CD-R and CD-RW. A CD-Ris for read-only permanent storage; the user cannot modify its contents once they are recorded. ACD-RWcan be used like a hard disk; that is, you can write data onto the disc, and then over-write that data with new data. A single CD can hold up to 700 MB. Most new PCs are equipped with a CD-RW drive that can work with both CD-R and CD-RW discs.
DVDstands for digital versatile disc or digital video disc. DVDs and CDs look alike, and you can use either to store data. A DVD can hold more information than a CD; a standard DVD’s storage capacity is 4.7 GB. Like CDs, there are two types of DVDs: DVD-R (read-only) and DVD-RW (rewritable).
drive
hard disk
CD-R
CD-RW
1.2 What Is a Computer?
7
FIGURE1.5 USB flash drives are very portable and can store a lot of data.
Function
Modifier
Numeric Keypad Page Up
Insert
Delete
Page Down
Arrows
FIGURE1.6 A computer keyboard consists of the keys for sending input to a computer.
USB Flash Drives
Universal serial bus (USB) connectors allow the user to attach many kinds of peripheral devices to the computer. You can use a USB to connect a printer, digital camera, mouse, exter-nal hard disk drive, and other devices to the computer.
A USB flash driveis a device for storing and transporting data. A flash drive is small— about the size of a pack of gum, as shown in Figure 1.5. It acts like a portable hard drive that can be plugged into your computer’s USB port. USB flash drives are currently available with up to 256 GB storage capacity.
1.2.5
Input and Output Devices
Input and output devices let the user communicate with the computer. The most common input devices are keyboardsandmice.The most common output devices are monitorsandprinters.
The Keyboard
A keyboard is a device for entering input. Figure 1.6 shows a typical keyboard. Compact key-boards are available without a numeric keypad.
Function keysare located across the top of the keyboard and are prefaced with the letter F.
Their functions depend on the software currently being used.
Amodifier keyis a special key (such as the Shift,Alt, and Ctrlkeys) that modifies the nor-mal action of another key when the two are pressed simultaneously.
Thenumeric keypad, located on the right side of most keyboards, is a separate set of keys styled like a calculator to use for entering numbers quickly.
Arrow keys,located between the main keypad and the numeric keypad, are used to move the mouse pointer up, down, left, and right on the screen in many kinds of programs.
TheInsert,Delete,Page Up, and Page Down keysare used in word processing and other programs for inserting text and objects, deleting text and objects, and moving up or down through a document one screen at a time.
The Mouse
Amouseis a pointing device. It is used to move a graphical pointer (usually in the shape of an arrow) called a cursoraround the screen or to click on-screen objects (such as a button) to trigger them to perform an action.
The Monitor
The monitor displays information (text and graphics). The screen resolution and dot pitch determine the quality of the display.
Thescreen resolutionspecifies the number of pixels in horizontal and vertical dimensions of the display device. Pixels(short for “picture elements”) are tiny dots that form an image on the screen. A common resolution for a 17-inch screen, for example, is 1,024 pixels wide and 768 pixels high. The resolution can be set manually. The higher the resolution, the sharper and clearer the image is.
Thedot pitchis the amount of space between pixels, measured in millimeters. The smaller the dot pitch, the sharper the display.
1.2.6
Communication Devices
Computers can be networked through communication devices, such as a dial-up modem
(modulator/demodulator), a DSL or cable modem, a wired network interface card, or a wire-less adapter.
■ A dial-up modem uses a phone line and can transfer data at a speed up to 56,000 bps (bits per second).
■ Adigital subscriber line (DSL)connection also uses a standard phone line, but it can transfer data 20 times faster than a standard dial-up modem.
■ Acable modemuses the cable TV line maintained by the cable company and is gen-erally faster than DSL.
■ Anetwork interface card (NIC)is a device that connects a computer to a local area network (LAN), as shown in Figure 1.7. LANs are commonly used in universities, businesses, and government agencies. A high-speed NIC called 1000BaseT can transfer data at 1,000 million bits per second (mbps).
■ Wireless networking is now extremely popular in homes, businesses, and schools. Every laptop computer sold today is equipped with a wireless adapter that enables the computer to connect to a local area network and the Internet.
Note
Answers to checkpoint questions are on the Companion Website.
1.1
What are hardware and software?1.2
List five major hardware components of a computer.1.3
What does the acronym “CPU” stand for?modifier key
numeric keypad
arrow keys
Insert key Delete key Page Up key Page Down key
screen resolution pixels
dot pitch
modem
digital subscriber line (DSL)
cable modem
network interface card (NIC) local area network (LAN)
million bits per second (mbps)
1.3 Programming Languages
9
Network Interface Card
LAN
FIGURE1.7 A local area network connects computers in close proximity to each other.
1.4
What unit is used to measure CPU speed?1.5
What is a bit? What is a byte?1.6
What is memory for? What does RAM stand for? Why is memory called RAM?1.7
What unit is used to measure memory size?1.8
What unit is used to measure disk size?1.9
What is the primary difference between memory and a storage device?1.3 Programming Languages
Computerprograms, known as software, are instructions that tell a computer what to do.
Computers do not understand human languages, so programs must be written in a language a computer can use. There are hundreds of programming languages, and they were developed to make the programming process easier for people. However, all programs must be converted into a language the computer can understand.
1.3.1
