Table Of ContentiOS 14 Programming
for Beginners
Fifth Edition
Get started with building iOS apps with Swift 5.3
and Xcode 12
Ahmad Sahar
BIRMINGHAM—MUMBAI
iOS 14 Programming for Beginners
Fifth Edition
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First published: January 2017
Second Edition: January 2018
Third Edition: December 2018
Fourth Edition: January 2020
Fifth Edition: November 2020
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To my beloved wife, Oni.
Ahmad Sahar
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Contributors
About the author
Ahmad Sahar is a trainer, presenter, and consultant at Tomafuwi Productions,
specializing in conducting training courses for macOS and iOS, macOS Support Essentials
certification courses, and iOS development courses. He is a member of the DevCon iOS
and MyCocoaHeads online communities in Malaysia, and has conducted presentations
and talks for both groups. In his spare time, he likes building and programming LEGO
Mindstorms robots.
About the reviewers
Robin Douglas is an experienced software engineer specializing in native iOS
development, and is a computer science graduate from the University of Leeds, UK.
While at the UoL, he conducted research into iOS development for use in education. He
is currently working on new native iOS apps for Sky Betting & Gaming. Some other large
projects he has worked on recently are Odhealth (formally known as HealthPod), which
facilitates virtual sessions with personal trainers, and Artuoso, a social network for artists.
Tom Holmes is an iOS developer and software engineer with intense training in Swift
5 and iOS development practices, such as test-driven development, SOLID principles,
MVC, MVVM, and frameworks both native to Apple and from third parties. He has
a great interest in how software can be applied to the financial sector to make investing
by analyzing stocks easier and more accessible to the masses, and how apps can help
achieve this vision. He also has an interest in how machine learning and AI will shape the
landscape of investing in the near future, and wishes to play a part in this future. He's very
passionate about technology and wishes to build a great career in it. His other areas of
expertise include Python 3, NumPy, JavaScript, SQL, and some web development.
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Table of Contents
Preface
Section 1:
Swift
1
Getting Familiar with Xcode
Technical requirements 4 Running the app in the iOS
Downloading and installing simulator 10
Xcode from the App Store 4 Using an iOS device for
Understanding the Xcode user development 13
interface 8 Connecting an iOS device wirelessly 20
Summary 22
2
Simple Values and Types
Technical requirements 24 Using common data types in the
playground 31
Understanding Swift Playgrounds2 4
Customizing fonts and colors 27 Exploring constants and
Running playground code 28 variables 32
Understanding type inference
Exploring data types 29
and type safety 34
Representing integers 29
Using type annotation to specify a type 35
Representing floating-point numbers 29
Using type safety to check values 36
Representing Booleans 30
Representing strings 30 Exploring operators 36
Using arithmetic operators 37 Performing string operations 41
Using compound assignment operators 38
Using the print() instruction 42
Using comparison operators 39
Summary 43
Using logical operators 40
3
Conditionals and Optionals
Technical requirements 46 Introducing optionals 50
Introducing conditionals 46 Using optionals and optional binding 51
Using if statements 47
Summary 55
Using switch statements 49
4
Range Operators and Loops
Technical requirements 58 Using the while loop 62
Exploring range operators 58 The repeat-while loop 62
Exploring loops 60 Summary 63
Using the for-in loop 60
5
Collection Types
Technical requirements 65 Checking the number of elements in a
dictionary 71
Understanding arrays 66
Adding a new element to a dictionary 72
Creating an array 67
Accessing a dictionary element 72
Checking the number of elements in
Assigning a new value to an existing key 73
an array 67
Removing an element from a dictionary 73
Adding a new element to an array 68
Iterating over a dictionary 74
Accessing an array element 68
Assigning a new value to a particular Understanding sets 74
index 69
Creating a set 75
Removing an element from an array 69
Checking the number of elements in a
Iterating over an array 70
set 75
Understanding dictionaries 70 Adding a new element to a set 76
Creating a dictionary 71
Checking whether a set contains an Exploring set operations 77
element 76 Exploring set membership and equality 78
Removing an item from a set 76
Summary 79
Iterating over a set 77
6
Functions and Closures
Technical requirements 82 Using a guard statement to exit a
function early 87
Understanding functions 82
Creating a function 83 Understanding closures 88
Using custom argument labels 84
Simplifying closures 89
Using nested functions 84
Summary 90
Using functions as return types 85
Using functions as parameters 86
7
Classes, Structures, and Enumerations
Technical requirements 92 Comparing value types and references
types 101
Understanding classes 92
Deciding between classes and
Creating a class declaration 93
structures 103
Making an instance of the class 94
Making a subclass 96 Understanding enumerations 103
Overriding a superclass method 97 Creating an enumeration 104
Understanding structures 99 Summary 105
Creating a structure declaration 100
Making an instance of the structure 101
8
Protocols, Extensions, and Error Handling
Technical requirements 108 Understanding extensions 111
Understanding protocols 108 Adopting a protocol via an extension 112
Creating a protocol declaration 110
