Special Features

xvii

Array Construction

282

Array Element Access

283

Assertion

337

Assignment

37

Block Statement

193

Calling a Superclass Constructor

481

Calling a Superclass Method

479

Cast

106

Class Definition

73

Constant Definition

112

Constructor Definition

72

Defining a Generic Class

846

Defining a Generic Method

853

Defining an Enumerated Type

213

Defining an Interface

414

Exception Specification

557

finally

Clause

562

General

try Block 559

Implementing an Interface 414Importing a Class from a Package 48Inheritance 471Inner Classes 425Instance Field Declaration 78Instantiating a Generic Class 843

Method Call 21Method Definition 71

Object Construction 45

Package Specification 352

Static Method Call 124

The “for each” Loop 293The for Statement 241The if Statement 192The instanceof Operator 484The return Statement 81The while Statement 236Throwing an Exception 555

Variable Definition 35

Alphabetical List of Syntax Boxes

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xviii Table of Special Features

Chapter Common Errors How Tos Quality Tips

1 Introduction Omitting Semicolons 22

Misspelling Words 24

2 Using Objects Trying to Invoke a Constructor Like a Method 46

3 Implementing Classes Forgetting to Initialize Object References in a Constructor 90

Trying to Call a Method Without an Implicit Parameter 93

Designing and Implementing a Class 85

4 Fundamental Data Types

Integer Division 121

Unbalanced Parentheses 122

Roundoff Errors 125

Carrying Out Computations 125

Do Not Use Magic Numbers 115

Choose Descriptive Variable Names 115

White Space 122

Factor Out Common Code 123

5 Programming Graphics (Optional)

Drawing Graphical Shapes 170

Calculate Sample Data Manually 183

6 Decisions Using == to Compare Strings 198

The Dangling else Problem 210

Multiple Relational Operators 216

Confusing && and || Conditions 217

Brace Layout 193

Avoid Conditions with Side Effects 201

Prepare Test Cases Ahead of Time 211

7 Iteration Infinite Loops 236

Off-by-One Errors 237

Forgetting a Semicolon 246

A Semicolon Too Many 246

Implementing Loops 254 Use for Loops for Their Intended Purpose 245

Don’t Use != to Test the End of a Range 247

Symmetric and Asymmetric Bounds256

Count Iterations 256

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Table of Special Features xix

Productivity Hints Advanced Topics Random Facts

Understand the File System 15

Have a Backup Strategy 16

Alternative Comment Syntax 20 The ENIAC and the Dawn of Computing 7

Don’t Memorize—Use Online Help 52

Testing Classes in an Interactive Environment 49

Mainframes—When Dinosaurs Ruled the Earth 55

The javadoc Utility 76

Using the Command Line Effectively 88

Calling One Constructor from Another 93

Electronic Voting Machines 94

Avoid Unstable Layout 117

Reading Exception Reports 130

Big Numbers 107

Binary Numbers 107

Combining Assignment and Arithmetic 118

Escape Sequences 131

Strings and the char Type 132

Formatting Numbers 137

Reading Input from a Dialog Box 139

The Pentium Floating-Point Bug 109

International Alphabets 133

Applets 158 The Evolution of the Internet 160

Computer Graphics 174

Indentation and Tabs 194

Keyboard Shortcuts for Mouse Operations 203

Copy and Paste in the Editor 204

Make a Schedule and Make Time for Unexpected Problems 212

The Selection Operator 195

The switch Statement 205

Enumerated Types 212

Lazy Evaluation of Boolean Operators 217

De Morgan’s Law 218

Artificial Intelligence 219

do Loops 238

Scope of Variables Defined in a for Loop Header 247

The “Loop and a Half” Problem 257

The break and continue Statements 258

Loop Invariants 265

Spaghetti Code 239

Correctness Proofs 267

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xx Table of Special Features

Chapter Common Errors How Tos Quality Tips

8 Arrays and Array Lists Bounds Errors 283

Uninitialized Arrays 284

Length and Size 289

Underestimating the Size of a Data Set 307

Working with Array Lists and Arrays 301

Prefer Parameterized Array Lists 289

Make Parallel Arrays into Arrays of Objects 307

9 Designing Classes Trying to Modify Primitive Type Parameters 331

Shadowing 349

Confusing Dots 356

Programming with Packages 356

Consistency 328

Minimize Side Effects 333

Don’t Change the Contents of Parameter Variables 333

10 Testing and Debugging

Debugging 398

11 Interfaces and Polymorphism

Forgetting to Define Implementing Methods as Public 415

Trying to Instantiate an Interface 418

Modifying the Signature in the Implementing Method 430

12 Event Handling (Optional)

Forgetting to Attach a Listener 450

Forgetting to Repaint 459

Implementing a Graphical User Interface (GUI) 453

13 Inheritance Confusing Super- and Subclasses 472

Shadowing Instance Fields 479

Failing to Invoke the Superclass Method 480

Accidental Package Access 493

Making Inherited Methods Less Accessible 493

Defining the equals Method with the WrongParameter Type 500

Forgetting to Clone 502

Clone Mutable Instance Fields in Accessor Methods 502

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Table of Special Features xxi

Productivity Hints Advanced Topics Random Facts

Array Initialization 284

Two-Dimensional Arrays with Variable Row Lengths 302

Multidimensional Arrays 302

Partially Filled Arrays 308

Methods with a Variable Number of Parameters 309

An Early Internet Worm 310

Global Search and Replace 350

Regular Expressions 350

Call by Value and Call by Reference 334

Class Invariants 339

Alternative Forms of Field Initialization 345

Static Imports 351

The Explosive Growth of Personal Computers 358

Batch Files and Shell Scripts 385 Reading Test Inputs from a File 379

Unit Testing with JUnit 386

The First Bug 399

The Therac-25 Incidents 400

Constants in Interfaces 416

Anonymous Classes 426

Operating Systems 433

Don’t Use a Container as a Listener 450

Code Reuse 454

Event Adapters 459 Programming Languages 460

Supply toString in All Classes 497

Abstract Classes 490

Final Methods and Classes 491

Protected Access 494

Inheritance and the toStringMethod 497

Inheritance and the equalsMethod 500

Implementing the clone Method 503

Enumerated Types Revisited 505

Scripting Languages 506

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xxii Table of Special Features

Chapter Common Errors How Tos Quality Tips

14 Graphical User Interfaces (Optional)

Layout Management 528

15 Exception Handling Throw Early, Catch Late 560

Do Not Squelch Exceptions 560

Do Not Use catch and finally in the Same try Statement 562

Do Throw Specific Exceptions 564

16 Files and Streams Backslashes in File Names 578

Negative byte Values 582

Using Files and Streams 597

17 Object-Oriented Design

CRC Cards and UML Diagrams 619

18 Recursion Infinite Recursion 668

Tracing Through Recursive Methods 672

Thinking Recursively 673

19 Sorting and Searching The compareTo Method Can Return Any Integer, Not Just –1, 0, and 1 732

20 An Introduction to Data Structures

21 Advanced Data Structures

Forgetting to Define hashCode 795

Choosing a Container 813 Use Interface References to Manipulate Data Structures 780

22 Generic Programming Genericity and Inheritance 854

Writing Code That Does Not Work After Types Are Erased 857

Using Generic Types in a Static Context 858

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Table of Special Features xxiii

Productivity Hints Advanced Topics Random Facts

Adding the main Method to the Frame Class 517

Visual Programming 544

The Ariane Rocket Incident 569

Use Object Streams 599 File Dialog Boxes 578

Command Line Arguments 579

Serializing Geometric Objects 599

Encryption Algorithms 586

Attributes and Methods in UML Diagrams 620

Multiplicities 621

Aggregation and Association 621

Programmer Productivity 613

Software Development—Art or Science? 655

The Limits of Computation 684

Insertion Sort 713

Oh, Omega, and Theta 715

The Quicksort Algorithm 722

The Parameterized Comparable Interface 733

The Comparator Interface 733

The First Programmer 724

The Iterable Interface and the “For Each” Loop 746

Static Inner Classes 758

Standardization 765

Reverse Polish Notation 810

Software Piracy 814

Wildcard Types 855

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