PHP 5 Recipes: A Problem-Solution Approach (Problem-Solution Approach)

673 Pages·2005·5.53 MB·English

by  Lee Babin

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PHP 5 Recipes
A Problem-Solution Approach
Lee Babin, Nathan A. Good,
Frank M. Kromann, Jon Stephens
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PHP 5 Recipes: A Problem-Solution Approach
Copyright © 2005 by Lee Babin,Nathan A.Good,Frank M.Kromann,Jon Stephens
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Contents at a Glance
About the Authors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
About the Technical Reviewer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
■ CHAPTER 1 Overview of PHP Data Types and Concepts . . . . . . . . . . . . . . . . . . . . . . 1
■ CHAPTER 2 Overview of Classes,Objects,and Interfaces . . . . . . . . . . . . . . . . . . . 21
■ CHAPTER 3 Performing Math Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
■ CHAPTER 4 Working with Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
■ CHAPTER 5 Working with Dates and Times. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
■ CHAPTER 6 Working with Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
■ CHAPTER 7 Working with Files and Directories. . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
■ CHAPTER 8 Working with Dynamic Imaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
■ CHAPTER 9 Using Regular Expressions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
■ CHAPTER 10 Working with Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393
■ CHAPTER 11 Using Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437
■ CHAPTER 12 Understanding Web Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453
■ CHAPTER 13 Creating and Using Forms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487
■ CHAPTER 14 Working with Markup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513
■ CHAPTER 15 Using MySQL Databases in PHP 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551
■ CHAPTER 16 Communicating with Internet Services . . . . . . . . . . . . . . . . . . . . . . . . 597
■ INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 631
iii
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Contents
About the Authors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xv
About the Technical Reviewer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xix
■ CHAPTER 1 Overview of PHP Data Types and Concepts . . . . . . . . . . . . . . . . 1
1-1.Variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1-2.Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1-3.Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1-4.Strings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1-5.Regular Expressions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1-6.Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1-7.Project:Finding the Data Type of a Value. . . . . . . . . . . . . . . . . . . . . . . 10
1-8.Project:Discovering What Variables,Constants,
Functions,Classes,and Interfaces Are Available . . . . . . . . . . . . . . . . . . 12
1-9.Getting Information About the Current Script. . . . . . . . . . . . . . . . . . . . 14
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
■ CHAPTER 2 Overview of Classes,Objects,and Interfaces. . . . . . . . . . . . . 21
Understanding Basic Concepts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
2-1.Creating Instances Using Constructors. . . . . . . . . . . . . . . . . . . . . . . . . 24
2-2.Using Default Constructors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
2-3.Setting Object Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
2-4.Controlling Access to Class Members. . . . . . . . . . . . . . . . . . . . . . . . . . 30
2-5.Using Static Members and the self Keyword. . . . . . . . . . . . . . . . . . . . 33
2-6.Using Class Constants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
2-7.Extending Classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
2-8.Using Abstract Classes and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . 50
2-9.Using Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2-10.Using Class Destructors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2-11.Using Exceptions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Getting Information About Classes and Objects. . . . . . . . . . . . . . . . . . . . . . 61
Using Class and Object Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
v
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2-12.Checking for the Existence of Classes and
Interfaces Using class_exists() and interface_exists(). . . . . . . . . . . . . . 63
2-13.Listing Methods and Interfaces Using get_class_methods(). . . . . . . 65
2-14.Obtaining Variable Names. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
2-15.Determining Whether an Object Is an Instance
of a Particular Class. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
2-16.Listing Currently Loaded Interfaces and Classes . . . . . . . . . . . . . . . 69
Using the Class Reflection API. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
2-17.Obtaining a Dump of the Reflection API . . . . . . . . . . . . . . . . . . . . . . . 73
2-18.Performing Dynamic Class Instantiation. . . . . . . . . . . . . . . . . . . . . . . 76
2-19.Using the Reflection API to Deconstruct the Shape Class. . . . . . . . 77
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
■ CHAPTER 3 Performing Math Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
3-1.Numeric Data Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
3-2.Random Numbers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
3-3.Logarithms and Exponents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
3-4.Trigonometric Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105
3-5.Formatting of Numeric Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
3-6.Math Libraries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
3-7.A Static Math Class. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
■ CHAPTER 4 Working with Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
4-1.Creating Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
4-2.Accessing Array Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
4-3.Creating Multidimensional Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
4-4.Using Array Keys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
4-5.Initializing an Array As a Range or Sequence of Values. . . . . . . . . . 124
Outputting Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
4-6.Outputting an Array As a String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
4-7.Outputting Using array_values() and array_keys()
for Backward Compatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126
4-8.Outputting an Array As a Tree. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Adding New Elements to Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131
4-9.Adding an Element to the End of an Array . . . . . . . . . . . . . . . . . . . . . 131
4-10.Appending One Array to Another . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
4-11.Comparing Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
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4-12.Adding an Element to the Beginning of an Array. . . . . . . . . . . . . . . 137
4-13.Inserting New Values at an Arbitrary Point
in an Indexed Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Getting and Setting the Size of an Array. . . . . . . . . . . . . . . . . . . . . . . . . . . 139
4-14.Counting Array Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
4-15.Setting an Array’s Size. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Traversing Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144
4-16.Looping Through an Associative Array Using foreach. . . . . . . . . . . 144
4-17.Looping Through a Compact Indexed Array
Using for and count(). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
4-18.Looping Through a Sparse Array . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
Removing Elements from Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
4-19.Removing the First or Last Element from an Array. . . . . . . . . . . . . 148
4-20.Removing One or More Arbitrary Array Elements. . . . . . . . . . . . . . 150
4-21.Extracting a Portion of an Array. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152
4-22.Extracting Values from Arrays with extract() . . . . . . . . . . . . . . . . . . 154
4-23.Extracting Values from an Array Using list(). . . . . . . . . . . . . . . . . . . 156
4-24.Combining Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
4-25.Obtaining Array Keys and Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
4-26.Working with Unique Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
4-27.Getting and Displaying Counts of Array Values . . . . . . . . . . . . . . . . 161
Finding and Working with Array Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
4-28.Determining Whether an Element Is in an Array. . . . . . . . . . . . . . . 163
4-29.Testing for the Existence of a Key in an Array. . . . . . . . . . . . . . . . . 164
4-30.Obtaining Array Keys with a Given Value . . . . . . . . . . . . . . . . . . . . . 165
4-31.Finding the Greatest and Least Values in an Array. . . . . . . . . . . . . 166
4-32.Finding the Sum and Average of the Values in an Array . . . . . . . . 168
Applying Functions to Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169
4-33.Applying Functions to Array Elements Using array_walk() . . . . . . 170
4-34.Applying Functions to Array Elements Using array_map(). . . . . . . 173
4-35.Filtering Arrays Using array_filter() . . . . . . . . . . . . . . . . . . . . . . . . . . 175
Sorting Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
4-36.Sorting an Array by Its Values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
4-37.Sorting an Array by Its Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180
4-38.Reversing an Array Using arsort() . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
4-39.Reversing an Array Using krsort() . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
4-40.Reversing an Array Using array_reverse() . . . . . . . . . . . . . . . . . . . . 182
4-41.Randomizing an Array Using shuffle(),kshuffle(),
and array_rand(). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
4-42.Sorting an Array Using Comparison Functions . . . . . . . . . . . . . . . . 184
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4-43.Sorting Multidimensional Arrays . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
4-44.Sorting Multiple Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189
Finding Permutations and Combinations. . . . . . . . . . . . . . . . . . . . . . . . . . . 190
4-45.Finding All Permutations of an Array’s Elements. . . . . . . . . . . . . . . 190
4-46.Finding All Combinations of an Array’s Elements . . . . . . . . . . . . . . 193
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
■ CHAPTER 5 Working with Dates and Times . . . . . . . . . . . . . . . . . . . . . . . . . . . 197
Overview of PHP 5’s Date and Time Functions. . . . . . . . . . . . . . . . . . . . . . 198
Displaying Dates and Times . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
5-1.Displaying Human-Readable Dates and Times . . . . . . . . . . . . . . . . . 201
5-2.Displaying Arbitrary Dates and Times. . . . . . . . . . . . . . . . . . . . . . . . . 204
5-3.Converting Human-Readable Dates Into Unix
Timestamps Using strtotime() . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
5-4.Finding the Date for a Weekday. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
5-5.Getting the Day and Week of the Year. . . . . . . . . . . . . . . . . . . . . . . . . 211
5-6.Determining Whether a Given Year Is a Leap Year. . . . . . . . . . . . . . . 213
5-7.Getting Times and Dates of Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214
5-8.Setting Time Zones and GMT/UTC. . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
5-9.Displaying Times and Dates in Other Languages . . . . . . . . . . . . . . . 219
5-10.Generating Localized GMT/UTC Time and Date Strings. . . . . . . . . 224
5-11.Obtaining the Difference Between Two Dates. . . . . . . . . . . . . . . . . 225
5-12.Project:Constructing and Using a Date Class. . . . . . . . . . . . . . . . . 231
5-13.Extending the Date Class . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
■ CHAPTER 6 Working with Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 265
Manipulating Substrings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266
6-1.Testing for Substrings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
6-2.Counting the Occurrences of a Substring. . . . . . . . . . . . . . . . . . . . . . 269
6-3.Accessing Substrings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269
6-4.Using Substring Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
6-5.Replacing Substrings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271
Processing Strings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
6-6.Joining and Disassembling Strings. . . . . . . . . . . . . . . . . . . . . . . . . . . 273
6-7.Reversing Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
6-8.Controlling Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277
6-9.Trimming Blank Spaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279
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■ CONTENTS ix
6-10.Wrapping Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280
6-11.Checking String Length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
6-12.Comparing Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283
6-13.Comparing Sound. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284
Project:Creating and Using a String Class. . . . . . . . . . . . . . . . . . . . . . . . . 285
6-14.Using a Page Reader Class. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290
■ CHAPTER 7 Working with Files and Directories. . . . . . . . . . . . . . . . . . . . . . . 291
Working with Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
7-1.Opening Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
7-2.Reading from Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
7-3.Writing to Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295
7-4.Closing Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
7-5.Reading and Writing Comma-Separated Data. . . . . . . . . . . . . . . . . . 298
7-6.Reading Fixed-Width Delimited Data. . . . . . . . . . . . . . . . . . . . . . . . . . 300
7-7.Reading and Writing Binary Data in a File . . . . . . . . . . . . . . . . . . . . . 301
7-8.Getting the Number of Lines in a File . . . . . . . . . . . . . . . . . . . . . . . . . 303
7-9.Getting the Number of Characters,Words,
or Paragraphs in a File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304
7-10.Project:Creating and Using a File Class. . . . . . . . . . . . . . . . . . . . . . 305
Working with Directories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
7-11.Listing All Files in the Current Directory. . . . . . . . . . . . . . . . . . . . . . 310
7-12.Listing All Files of a Certain Type. . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
7-13.Sorting Files by Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313
7-14.Generating a Recursive Directory Listing. . . . . . . . . . . . . . . . . . . . . 314
7-15.Using the SPL DirectoryIterator Object. . . . . . . . . . . . . . . . . . . . . . . 316
Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
Looking Ahead. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319
■ CHAPTER 8 Working with Dynamic Imaging. . . . . . . . . . . . . . . . . . . . . . . . . . . 321
Working with Image Types. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
8-1.Working with JPGs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321
8-2.Working with GIFs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 323
8-3.Working with PNGs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Working with Image Libraries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
Creating an Image from Scratch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
8-4.Creating a Blank Canvas. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
8-5.Creating and Using Colors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329