Stefan Kaczmarek, Brad Lees and Gary Bennett

Swift 5 for Absolute BeginnersLearn to Develop Apps for iOS5th ed.

Stefan Kaczmarek

Phoenix, AZ, USA

Brad Lees

Phoenix, AZ, USA

Gary Bennett

Scottsdale, AZ, USA

Any source code or other supplementary material referenced by the author in this book is available to readers on GitHub via the book’s product page, located at www.​apress.​com/​978-1-4842-4867-6 . For more detailed information, please visit http://​www.​apress.​com/​source-code .

ISBN 978-1-4842-4867-6e-ISBN 978-1-4842-4868-3

https://doi.org/10.1007/978-1-4842-4868-3

© Stefan Kaczmarek, Brad Lees, Gary Bennett 2019

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Introduction

Over the last ten years, we’ve heard the following countless times:

• “I’ve never programmed before, but I have a great idea for an iPhone or iPad app.”

• “Can I really learn to program the iPhone or iPad?”

To the latter we answer, “Yes, but you have to believe you can.” Only you are going to tell yourself you can’t do it.

For the Newbie

This book assumes you may have never programmed before. The book is also written for someone who may have never programmed before using object-oriented programming (OOP) languages. There are many Swift books out there, but all of these books assume you have programmed before and know OOP and computer logic. We wanted to write a book that takes readers from knowing little or nothing about computer programming and logic to being able to program in Swift. After all, Swift is a native programming language for the iPhone, iPad, and Mac.

Over the last ten years, we have taught thousands of students to be iOS (iPhone/iPad) developers. Many of our students have developed some of the most successful iOS apps in their category in the App Store. We have incorporated what we have learned in our first two courses, Introduction to Object-Oriented Programming and Logic and Swift for iPhone/iPad Developers, into this book.

For the More Experienced

Many developers who programmed years ago or programmed in a non-OOP language need a background in OOP and Logic before they dive into Swift. This book is for you. We gently walk you through OOP and how it is used in iOS development to help make you a successful iOS developer.

How This Book Is Organized

You’ll notice that we are all about successes in this book. We introduce the OOP and Logic concepts in Swift Playgrounds and then move those concepts to Xcode. Many students are visual or learn by doing. We use both techniques. We’ll walk you through topics and concepts with visual examples and then take you through step-by-step examples reinforcing the concepts.

We often repeat topics in different chapters to reinforce what you have learned and apply these skills in new ways. This enables new programmers to reapply development skills and feel a sense of accomplishment as they progress. Don’t worry if you feel you haven’t mastered a topic. Keep moving forward!

The Formula for Success

Learning to program is an interactive process between your program and you. Just like learning to play an instrument, you have to practice. You must work through the examples and exercises in this book. Understanding a concept doesn’t mean you know how to apply it and use it.

You will learn a lot from this book. You will learn a lot from working through the exercises in this book. However, you will really learn when you debug your programs. Spending time walking through your code and trying to find out why it is not working the way you want is an unparalleled learning process. The downside of debugging is a new developer can find it especially frustrating. If you have never wanted to throw your computer out the window, you will. You will question why you are doing this, and whether you are smart enough to solve the problem. Programming is very humbling, even for the most experienced developer.

Like a musician, the more you practice the better you get. By practicing, we mean programming! You can do some amazing things as a programmer. The world is your oyster. Seeing your app in the App Store is one of the most satisfying accomplishments. However, there is a price, and that price is time spent coding and learning.

Having taught many students to become iOS developers, we have put together a formula for what makes students successful. Here is our formula for success:

• Believe you can do it. You’ll be the only one who says you can’t do this. So don’t tell yourself that.

• Work through all the examples and exercises in this book.

• Code, code, and keeping coding. The more you code, the better you’ll get.

• Be patient with yourself. If you were fortunate enough to have been a 4.0 student who can memorize material just by reading it, this will not happen with Swift coding. You are going to have to spend time coding.

• You learn by reading this book. You really learn by debugging your code.

• Don’t give up!

The Development Technology Stack

We will walk you through the process of understanding the development process for your iOS apps and what technology you need. However, briefly looking at all the technology pieces together is helpful. These are the key iOS development technologies you will need to know in order to build a successful app and get it on the App Store:

• Apple Developer web site

• App Analytics

• iOS SDK

• Swift

• Object-Oriented Programming and Logic

• Xcode Integrated Development Environment (IDE)

• Debugging

• Performance Tuning

We know this is a lot of technology. Don’t worry, we will go through it and will be comfortable using it.

Required Software, Materials, and Equipment

One of the great things about developing iOS apps is just about everything is free to develop your app.

• Xcode

• Swift

• macOS 10.14 or higher

• iOS SDK

• iOS Simulator

All you need to get started is a Mac and knowledge of where to download everything. We will cover this.

Operating System and IDE

For developing iOS apps, you have to use Xcode on a Mac. You can download Xcode for free from the Mac App Store (see Figure 1 ).

Figure 1

Downloading Xcode from the Mac App Store

Software Development Kits

You will need to register as a developer. You can do this for free at https://developer.apple.com/ios (see Figure 2 ).

Figure 2

Apple Developer web site

When you are ready to upload your app to the App Store, you will need to pay $99/year in order to publish it.

Dual Monitors

We recommend developers have a second monitor connected to their computer. It is great to step through your code and watch your output window and iOS simulator at the same time on dual independent monitors.

Apple hardware makes this easy. Just plug your second monitor into the port of any Mac, with the correct adapter of course, and you have two monitors working independently of one another. See Figure 3 . Note that dual monitors are not required. You will just have to organize your open windows to fit on your screen if you don’t.

Figure 3

Arranging dual monitors on a Mac

Table of Contents

Chapter 1:​ Becoming a Great iOS Developer 1

Thinking like a Developer 1

Completing the Development Cycle 5

Introducing Object-Oriented Programming 7

Working with the Playground Interface 11

Summary 12

What’s Next 13

Chapter 2:​ Programming Basics 15

Touring Xcode 15

Exploring the Workspace Window 16

Navigating Your Workspace 18

Editing Your Project Files 19

Creating Your First Swift Playground Program 21

Installing and Launching Xcode 10.​2 21

Using Xcode 10.​2 23

Xcode Playground IDE:​ Editor and Results Areas 25

Summary 27

Chapter 3:​ It’s All About the Data 29

Numbering Systems Used in Programming 29

Bits 29

Bytes 31

Hexadecimal 33

Unicode 35

Data Types 35

Declaring Constants and Variables 36

Optionals 38

Using Variables in Playgrounds 39

Summary 43

Chapter 4:​ Making Decisions, Program Flow, and App Design 45

Boolean Logic 46

Truth Tables 47

Comparison Operators 49

Designing Apps 50

Pseudocode 50

Optionals and Forced Unwrapping 54

Flowcharting 56

Designing and Flowcharting an Example App 57

The App’s Design 58

Using Loops to Repeat Program Statements 59

Coding the Example App in Swift 61

Nested if Statements and else if Statements 65

Removing Extra Characters 65

Improving the Code Through Refactoring 66

Running the App 66

Design Requirements 68

Summary 71

Chapter 5:​ Object-Oriented Programming with Swift 75

The Object 76

What Is a Class?​ 77

Planning Classes 78

Planning Properties 78

Planning Methods 81

Implementing the Classes 83

Inheritance 91

Why Use OOP?​ 92

OOP Is Everywhere 93

Eliminate Redundant Code 93

Ease of Debugging 93

Ease of Replacement 93

Advanced Topics 94

Interface 94

Polymorphism 94

Value Orientated Programming 95

Summary 96

Chapter 6:​ Learning Swift and Xcode 97

A Newcomer 97

Understanding the Language Symbols 98

Implementing Objects in Swift 99

Writing Another Program in Xcode 102

Creating the Project 102

Summary 119

Chapter 7:​ Swift Classes, Objects, and Methods 121

Creating a Swift Class 121

Properties 123

Methods 123

Using Your New Class 126

Creating Your Project 126

Adding Objects 129

Writing the Class 133

Creating the User Interface 136

Hooking Up the Code 140

Running the Program 144

Taking Type Methods to the Next Level 145

Accessing the Xcode Documentation 146

Summary 147

Chapter 8:​ Programming Basics in Swift 149

Using let vs.​ var 149

Understanding Collections 150

Using Arrays 150

Using the Dictionary Class 153

Creating the BookStore Application 155

Creating Your Class 159

Introducing Properties 160

Accessing Properties 161

Finishing the BookStore Program 162

Creating the View 162

Adding Properties 165

Adding a Description 167

Creating a Simple Data Model Class 169

Modifying the MasterViewContro​ller 171

Modifying the DetailViewContro​ller 175

Summary 177

Chapter 9:​ Comparing Data 179

Revisiting Boolean Logic 179

Using Relational Operators 180

Comparing Numbers 181

Creating an Example Xcode App 182

Using Boolean Expressions 186

Comparing Strings 187

Using the switch Statement 189

Comparing Dates 190

Combining Comparisons 192

Summary 193

Chapter 10:​ Creating User Interfaces 195

Understanding Interface Builder 196

The Model-View-Controller Pattern 197

Human Interface Guidelines 199

Creating an Example iPhone App with Interface Builder 201

Using Interface Builder 207

The Document Outline 209

The Object Library 209

Inspector Pane and Selector Bar 213

Creating the View 213

Using Outlets 216

Using Actions 220

The Class 222

Summary 225

Chapter 11:​ Storing Information 227

Storage Considerations 227

Preferences/​UserDefaults 228

Writing Preferences 228

Reading Preferences 230

Databases 231

Storing Information in a Database 231

Getting Started with Core Data 232

The Model 234

Managed Object Context 242

Setting Up the Interface 242

Summary 258

Chapter 12:​ Protocols and Delegates 261

Multiple Inheritance 261

Understanding Protocols 263

Protocol Syntax 264

Delegation 264

Protocol and Delegation Example 265

Getting Started 266

How It Works 278

Summary 279

Chapter 13:​ Introducing the Xcode Debugger 281

Getting Started with Debugging 282

Setting Breakpoints 283

Using the Breakpoint Navigator 285

Debugging Basics 287

Working with the Debugger Controls 290

Using the Step Controls 290

Looking at the Thread Window and Call Stack 292

Debugging Variables 292

Dealing with Code Errors and Warnings 294

Errors 294

Warnings 296

Summary 297

Chapter 14:​ A Swift iPhone App 299

Let’s Get Started 299

Switches 314

Alert Controllers 315

App Summary 323

Chapter 15:​ Apple Watch and WatchKit 325

Considerations When Creating a watchOS App 325

Creating an Apple Watch App 326

Adding More Functionality 344

Summary 351

Index 353

About the Authors and About the Technical Reviewer

About the Authors

Stefan Kaczmarek

has more than 20 years of software development experience specializing in mobile applications, large-scale software systems, project management, network protocols, encryption algorithms, and audio/video codecs. As chief software architect and cofounder of SKJM, LLC, Stefan developed a number of successful mobile applications including iCam (which has been featured on CNN , Good Morning America , and The Today Show , and which was chosen by Apple to be featured in the “Dog Lover” iPhone 3GS television commercial) and iSpy Cameras (which held the #1 Paid iPhone App ranking in a number of countries around the world including the United Kingdom, Ireland, Italy, Sweden, and South Korea). Stefan resides in Phoenix, Arizona, with his wife, Veronica, and their two children.

 

Brad Lees

has more than a decade of experience in application development and server management. He has specialized in creating and initiating software programs in real-estate development systems and financial institutions.

His career has been highlighted by his positions as information systems manager at The Lyle Anderson Company; product development manager for Smarsh; vice president of application development for iNation; and IT manager at The Orcutt/Winslow Partnership, the largest architectural firm in Arizona.

A graduate of Arizona State University, Brad resides in Phoenix with his wife Natalie and their five children.

 

Gary Bennett

teaches iPhone/iPad programming courses online. He has taught hundreds of students how to develop iPhone/iPad apps and has several very popular apps on the iTunes App Store. Gary’s students have some of the best-selling apps on the iTunes App Store. Gary also worked for 25 years in the technology and defense industries. He served 10 years in the US Navy as a nuclear engineer aboard two nuclear submarines. After leaving the Navy, Gary worked for several companies as a software developer, chief information officer, and resident. As CIO, he helped take VistaCare public in 2002. He also coauthored iPhone Cool Projects (Apress, 2009). Gary lives in Scottsdale, Arizona, with his wife, Stefanie, and their four children.

 

About the Technical Reviewer

Bruce Wade

is a software engineer from British Columbia, Canada. He started software development when he was 16 years old by coding his first web site. He went on to study Computer Information Systems at DeVry Institute of Technology in Calgary, then to further enhance his skills he studied Visual & Game Programming at The Art Institute of Vancouver. Over the years he has worked for large corporations as well as several start-ups. His software experience has led him to utilize many different technologies including C/C++, Python, Objective-C, Swift, Postgres, and JavaScript. In 2012, he started the company Warply Designed to focus on mobile 2D/3D and OS X development. Aside from hashing out new ideas, he enjoys spending time hiking with his Boxer Rasco, working out, and exploring new adventures.