Programming in Objective-C 2.0
Copyright © 2009 by Pearson Education, Inc.
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tion contained herein.
ISBN-13: 978-0-321-56615-7
ISBN-10: 0-321-56615-7
Library of Congress Cataloging-in-Publication Data:
Kochan, Stephen G.
Programming in Objective-C 2.0 / Stephen G. Kochan. -- 2nd ed.
p. cm.
ISBN 978-0-321-56615-7 (pbk.)
1. Objective-C (Computer program language) 2. Object-oriented
programming (Computer science) 3. Macintosh (Computer)--Programming.
I. Title.
QA76.73.O115K63 2009
005.1'17--dc22
2008049771
Printed in the United States of America
First Printing December 2008
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Table of Contents
Copyright..................................................................................................... 1
Developer’s Library
..................................................................................... 4
About the Author......................................................................................... 5
About the Technical Reviewers................................................................... 5
We Want to Hear from You!........................................................................ 6
Reader Services.......................................................................................... 6
Chapter 1. Introduction............................................................................... 8
What You Will Learn from This Book............................................................................................................................................ 9
How This Book Is Organized......................................................................................................................................................... 10
Acknowledgments......................................................................................................................................................................... 12
Part I: The Objective-C 2.0 Language......................................................... 14
Chapter 2. Programming in Objective-C....................................................................................................................................... 16
Compiling and Running Programs............................................................................................................................................ 16
Explanation of Your First Program........................................................................................................................................... 25
Displaying the Values of Variables............................................................................................................................................ 29
Summary................................................................................................................................................................................... 32
Exercises.................................................................................................................................................................................... 32
Chapter 3. Classes, Objects, and Methods.................................................................................................................................... 34
What Is an Object, Anyway?..................................................................................................................................................... 34
Instances and Methods............................................................................................................................................................. 35
An Objective-C Class for Working with Fractions.................................................................................................................... 37
The @interface Section............................................................................................................................................................. 40
The @implementation Section................................................................................................................................................. 44
The program Section................................................................................................................................................................. 45
Accessing Instance Variables and Data Encapsulation............................................................................................................. 51
Summary.................................................................................................................................................................................... 54
Exercises.................................................................................................................................................................................... 54
Chapter 4. Data Types and Expressions....................................................................................................................................... 56
Data Types and Constants......................................................................................................................................................... 56
Arithmetic Expressions............................................................................................................................................................. 63
Assignment Operators............................................................................................................................................................... 71
A Calculator Class...................................................................................................................................................................... 72
Bit Operators............................................................................................................................................................................. 74
Types: _Bool, _Complex, and _Imaginary.............................................................................................................................. 80
Exercises.................................................................................................................................................................................... 80
Chapter 5. Program Looping........................................................................................................................................................ 84
The for Statement...................................................................................................................................................................... 85
The while Statement.................................................................................................................................................................. 96
The do Statement..................................................................................................................................................................... 101
The break Statement............................................................................................................................................................... 102
The continue Statement.......................................................................................................................................................... 103
Summary.................................................................................................................................................................................. 103
Exercises.................................................................................................................................................................................. 103
Chapter 6. Making Decisions...................................................................................................................................................... 106
The if Statement...................................................................................................................................................................... 106
The switch Statement............................................................................................................................................................... 127
Boolean Variables.................................................................................................................................................................... 130
The Conditional Operator........................................................................................................................................................ 135
Exercises.................................................................................................................................................................................. 136
Chapter 7. More on Classes......................................................................................................................................................... 140
Separate Interface and Implementation Files........................................................................................................................ 140
Synthesized Accessor Methods................................................................................................................................................ 146
Accessing Properties Using the Dot Operator......................................................................................................................... 147
Multiple Arguments to Methods............................................................................................................................................. 148
Local Variables......................................................................................................................................................................... 153
The self Keyword...................................................................................................................................................................... 156
Allocating and Returning Objects from Methods................................................................................................................... 157
Exercises.................................................................................................................................................................................. 163
Chapter 8. Inheritance................................................................................................................................................................ 164
It All Begins at the Root........................................................................................................................................................... 164
Extension Through Inheritance: Adding New Methods......................................................................................................... 169
Overriding Methods
................................................................................................................................................................. 182
Extension Through Inheritance: Adding New Instance Variables......................................................................................... 188
Abstract Classes....................................................................................................................................................................... 190
Exercises................................................................................................................................................................................... 191
Chapter 9. Polymorphism, Dynamic Typing, and Dynamic Binding......................................................................................... 194
Polymorphism: Same Name, Different Class.......................................................................................................................... 194
Dynamic Binding and the id Type........................................................................................................................................... 198
Compile Time Versus Runtime Checking............................................................................................................................... 200
The id Data Type and Static Typing........................................................................................................................................ 201
Asking Questions About Classes............................................................................................................................................. 202
Exception Handling Using @try............................................................................................................................................. 207
Exercises.................................................................................................................................................................................. 210
Chapter 10. More on Variables and Data Types......................................................................................................................... 212
Initializing Classes................................................................................................................................................................... 212
Scope Revisited........................................................................................................................................................................ 214
Storage Class Specifiers.......................................................................................................................................................... 220
Enumerated Data Types.......................................................................................................................................................... 222
The typedef Statement............................................................................................................................................................ 225
Data Type Conversions............................................................................................................................................................ 227
Exercises.................................................................................................................................................................................. 229
Chapter 11. Categories and Protocols......................................................................................................................................... 232
Categories................................................................................................................................................................................ 232
Protocols.................................................................................................................................................................................. 238
Composite Objects................................................................................................................................................................... 242
Exercises.................................................................................................................................................................................. 243
Chapter 12. The Preprocessor..................................................................................................................................................... 246
The #define Statement............................................................................................................................................................ 246
The #import Statement........................................................................................................................................................... 254
Conditional Compilation......................................................................................................................................................... 257
Exercises.................................................................................................................................................................................. 260
Chapter 13. Underlying C Language Features............................................................................................................................ 262
Arrays...................................................................................................................................................................................... 263
Functions................................................................................................................................................................................. 269
Structures................................................................................................................................................................................ 278
Pointers................................................................................................................................................................................... 290
Unions..................................................................................................................................................................................... 309
They’re Not Objects!................................................................................................................................................................ 312
Miscellaneous Language Features........................................................................................................................................... 312
How Things Work.................................................................................................................................................................... 317
Exercises.................................................................................................................................................................................. 319
Part II: The Foundation Framework........................................................ 322
Chapter 14. Introduction to the Foundation Framework.......................................................................................................... 324
Foundation Documentation.................................................................................................................................................... 324
Chapter 15. Numbers, Strings, and Collections.......................................................................................................................... 328
Number Objects....................................................................................................................................................................... 329
String Objects.......................................................................................................................................................................... 333
Array Objects........................................................................................................................................................................... 348
Synthesized AddressCard Methods........................................................................................................................................ 356
Dictionary Objects................................................................................................................................................................... 374
Set Objects............................................................................................................................................................................... 377
Exercises.................................................................................................................................................................................. 382
Chapter 16. Working with Files.................................................................................................................................................. 384
Managing Files and Directories: NSFileManager.................................................................................................................. 385
Working with Paths: NSPathUtilities.h.................................................................................................................................. 396
Basic File Operations: NSFileHandle..................................................................................................................................... 404
Exercises.................................................................................................................................................................................. 409
Chapter 17. Memory Management.............................................................................................................................................. 412
The Autorelease Pool............................................................................................................................................................... 412
Reference Counting................................................................................................................................................................. 413
An Autorelease Example......................................................................................................................................................... 425
Summary of Memory-Management Rules............................................................................................................................. 426
Garbage Collection.................................................................................................................................................................. 427
Exercises.................................................................................................................................................................................. 429
Chapter 18. Copying Objects...................................................................................................................................................... 430
The copy and mutableCopy Methods...................................................................................................................................... 431
Shallow Versus Deep Copying
................................................................................................................................................. 433
Implementing the <NSCopying> Protocol............................................................................................................................. 436
Copying Objects in Setter and Getter Methods...................................................................................................................... 439
Exercises.................................................................................................................................................................................. 441
Chapter 19. Archiving................................................................................................................................................................. 442
Archiving with XML Property Lists........................................................................................................................................ 442
Archiving with NSKeyedArchiver........................................................................................................................................... 444
Writing Encoding and Decoding Methods............................................................................................................................. 447
Using NSData to Create Custom Archives.............................................................................................................................. 454
Using the Archiver to Copy Objects........................................................................................................................................ 457
Exercises.................................................................................................................................................................................. 459
Part III: Cocoa and the iPhone SDK........................................................ 460
Chapter 20. Introduction to Cocoa............................................................................................................................................. 462
Framework Layers................................................................................................................................................................... 462
Cocoa Touch............................................................................................................................................................................ 463
Chapter 21. Writing iPhone Applications................................................................................................................................... 466
The iPhone SDK...................................................................................................................................................................... 466
Your First iPhone Application................................................................................................................................................ 466
An iPhone Fraction Calculator................................................................................................................................................ 483
Summary................................................................................................................................................................................. 498
Exercises.................................................................................................................................................................................. 499
Part IV: Appendixes................................................................................ 502
Glossary....................................................................................................................................................................................... 504
Appendix B. Objective-C 2.0 Language Summary...................................................................................................................... 512
Digraphs and Identifiers.......................................................................................................................................................... 512
Comments................................................................................................................................................................................ 516
Constants.................................................................................................................................................................................. 517
Data Types and Declarations.................................................................................................................................................. 520
Expressions.............................................................................................................................................................................. 531
Storage Classes and Scope...................................................................................................................................................... 546
Functions................................................................................................................................................................................. 550
Classes...................................................................................................................................................................................... 553
Statements............................................................................................................................................................................... 563
Exception Handling................................................................................................................................................................ 568
Preprocessor............................................................................................................................................................................ 568
Appendix C. Address Book Source Code.................................................................................................................................... 576
AddressCard Interface File...................................................................................................................................................... 576
AddressBook Interface File..................................................................................................................................................... 577
AddressCard Implementation File.......................................................................................................................................... 577
AddressBook Implementation File......................................................................................................................................... 579
Appendix D. Resources............................................................................................................................................................... 582
Answers to Exercises, Errata, and Such................................................................................................................................. 582
Objective-C Language............................................................................................................................................................. 582
C Programming Language....................................................................................................................................................... 583
Cocoa....................................................................................................................................................................................... 583
iPhone and iTouch Application Development........................................................................................................................ 584
