Swift for the Really Impatient

Matt Henderson has been developing for Apple’s platforms since 2009 and is currently a Cocoa engineer at MartianCraft. He’s given several presentations at various user groups and conferences, including 360iDev, Cocoaheads Denver, and Boulder iOS Meetup. He realized he might have a future in software when he discovered it was easier for him to program his graphing calculator to solve equations than it was to study for his math tests. He thinks that the best debugging technique is taking a walk outside in the sun or snow. Dave Wood has been developing for iOS since 2008 and OS X since 2009. He began writing code at age 9 on a TI/99/4A and instantly fell in love. He has worked on various types of projects, including systems that interface with stock exchanges, news outlets, and banking systems, as well as newspaper websites and, of course, mobile apps ranging from games, social networks, financial apps, and productivity and developer apps. When possible, he enjoys whitewater kayaking and scuba diving. Currently he runs his own development studio, Cerebral Gardens, and freelances as a Cocoa engineer for MartianCraft.

Foreword   xi
Preface   xiii
Acknowledgments   xv
About the Authors    xvi
Chapter 1: Introducing Swift   1
1.1 Basic Syntax   2
1.1.1 Variables and Constants   2
1.1.2 String Interpolation   5
1.1.3 Control Flow   6
1.2 Basic Data Types   10
1.2.1 Int   10
1.2.2 Double and Float   12
1.2.3 Bool   13
1.2.4 Strings   14
1.2.5 Arrays   15
1.2.6 Dictionaries   19
Exercises   20
Chapter 2: Diving Deeper into Swift’s Syntax   21
2.1 Optionals   22
2.2 Generics   25
2.3 Type Annotations and Type Inference   28
2.4 Functions and Closures   29
2.4.1 Global Functions   30
2.4.2 Nested Functions   30
2.4.3 Closure Expressions   31
2.5 Tuples   32
2.6 switch Statements and Pattern Matching   34
Exercises   37
Chapter 3: Objects and Classes   39
3.1 Enumerations   41
3.2 Classes   45
3.3 Structures   49
3.4 Subclassing   51
3.5 Overloading   52
3.6 Overriding   54
3.7 Initialization   55
3.8 Properties   57
3.8.1 Computed Properties   59
3.8.2 Property Observers   60
3.8.3 lazy Properties   62
3.9 Subscripting   63
3.10 Protocols   65
3.11 Extensions   67
3.12 Access Control   68
Exercises   73
Chapter 4: Optionals   75
4.1 Optionals and nil   76
4.2 Validity Checking, Optional Binding, and Forced Unwrapping   78
4.3 Optional Chaining   81
4.4 Implicitly Unwrapped Optionals   86
Exercises   88
Chapter 5: Generics   91
5.1 Why Generics?    92
5.2 Generic Functions   92
5.2.1 Type Parameters   93
5.2.2 Using More Than One Type Parameter   94
5.3 Generic Types   94
5.3.1 Associated Types   98
5.3.2 The where Clause   100
Exercises   101
Chapter 6: Functions and Closures   103
6.1 Functions   104
6.1.1 Parameters   104
6.1.2 External Parameter Names   105
6.1.3 Default Parameter Values   107
6.1.4 Variadic and inout Parameters   108
6.1.5 Return Types   110
6.2 Closures   112
6.2.1 Inferring Parameters and the Return Value   113
6.2.2 Trailing Closures   113
6.3 Functional Programming Patterns   114
Exercises   117
Chapter 7: Working with Objective-C   119
7.1 Interacting with C and Objective-C APIs   120
7.1.1 Optional Properties and Return Values   122
7.1.2 AnyObject Types   123
7.1.3 Subclassing, Extensions, and Protocols   124
7.1.4 Automatically Converted Types   126
7.1.5 Selectors and Enums   128
7.1.6 Working with C Code   129
7.2 Working with Swift and Objective-C in a Single Project   130
Exercises   133
Chapter 8: Common Patterns   135
8.1 Nested Types   136
8.2 Singletons   137
8.3 Using Grand Central Dispatch   139
8.3.1 dispatch_once   139
8.3.2 dispatch_async   139
8.3.3 dispatch_after   140
8.3.4 dispatch_apply   140
8.4 Sequences and Generators   141
8.5 Operators   145
8.5.1 Operator Overloading   146
8.5.2 Custom Operators   147
Exercises   148
Index   149