Learning Swift

Andrew J Wagner

• Publisher: Packt Publishing
• Year: 2015
• ISBN:
  9781784392505
• Edition: 1
• Topic: Ciencia de la computación
• Subtopic: Programación

Learning Swift

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Table of Contents

Learning Swift

Credits

About the Author

About the Reviewer

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Errata

Piracy

Questions

1. Introducing Swift

Defining our goals for this book

Setting up the development environment

Running our first Swift code

Understanding playgrounds

Learning with this book

Summary

2. Building Blocks – Variables, Collections, and Flow Control

Core Swift types

Constants and variables

Containers

Tuples

Arrays

Dictionaries

Swift's type system

Printing on the console

Control flow

Conditionals

Switches

Loops

Functions

Basic functions

Parameterized functions

Functions that return values

Functions with default arguments

Bringing it all together

Summary

3. One Piece at a Time – Types, Scopes, and Projects

Structs

Types versus instances

Properties

Member and static methods

Computed properties

Reacting to property changes

Subscripts

Custom initialization

Classes

Inheriting from another class

Initialization

Overriding initializers

Required initializers

Designated and convenience initializers

Overriding methods and computed properties

Methods

Computed properties

Casting

Upcasting

Downcasting

Enumerations

Basic declaration

Testing enumeration values

Raw values

Associated values

Methods and properties

Projects

Setting up a command-line Xcode project

Creating and using an external file

Interfacing with code from other files

File organization and navigation

Extensions

Scope

How is scope defined

Nested types

Access control

Summary

4. To Be or Not to Be – Optionals

Introducing optionals

Unwrapping an optional

Optional binding

Forced unwrapping

Nil coalescing

Optional chaining

Implicitly unwrapped optionals

Debugging optionals

The underlying implementation

Summary

5. A Modern Paradigm – Closures and Functional Programming

Functional programming philosophy

State and side effects

Declarative versus imperative code

Closures

Closures as variables

Closures as parameters

Syntactic sugar

Building blocks of functional programming in Swift

The filter function

The reduce function

The map function

The sorted function

How these affect the state and nature of code

Lazy evaluation

Curried functions

Summary

6. Make Swift Work for You – Protocols and Generics

Protocols

Defining a protocol

Implementing a protocol

Using type aliases

Defining a generic

The generic function

The generic type

Type constraints

Protocol constraints

Where clauses for protocols

Where clauses for equality

Extending the existing generics

Enhancing arrays

Enhancing dictionaries

Putting protocols and generics to use

Generators

Sequences

Product of Fibonacci numbers under 50

Summary

7. Everything is Connected – Memory Management

How data is stored in a computer

Filesystem

Memory

Value types versus reference types

Determining a value or reference type

Behavior on assignment

Behavior on input

Capturing behavior of closure

Automatic reference counting

Object relationships

Strong relationships

Weak relationships

Unowned relationships

Strong reference cycles

Strong reference cycles between objects

Spotting

Fixing the cycles

With closures

Spotting

Fixing

Lost objects

Between objects

With closures

Summary

8. Writing Code the Swift Way – Design Patterns and Techniques

What is a design pattern?

Behavioral patterns

The iterator pattern

The observer pattern

The callback property

The notification center

Structural patterns

The composite pattern

Hierarchies

An alternative to subclassing

The delegate pattern

Model-View-Controller

Creational patterns

A singleton/shared instance

The abstract factory pattern

Using associated values effectively

Replacing class hierarchies

Concisely representing a state

Extending system types to reduce code

Lazy properties

Avoiding unnecessary memory usage

Avoiding unnecessary processing

Localizing logic to the concerned property

Summary

9. Harnessing the Past – Understanding and Translating Objective-C

Swift's relationship with Objective-C

The history of Objective-C

Constants and variables

Value types

Reference types

Containers

Arrays

Dictionaries

Control flow

Conditionals

Switches

Loops

Functions

Types

Structures

Enumerations

Classes

The basic class

Initializers

Properties

Methods

Inheritance

Categories

Protocols

Blocks

Projects

Header files

An implementation file

Organization

Calling Objective-C code from Swift

A bridging header

Using functions

Using types

Containers

Reference type translation

Summary

10. A Whole New World – Developing an App

Conceptualizing the app

Features

The interface

Data

Setting up the app project

Configuring the user interface

Running the app

Allowing picture taking

Temporarily saving a photo

Populating our photo grid

Refactoring to respect Model-View-Controller

Permanently saving a photo

Summary

11. What's Next? Resources, Advice, and Next Steps

Apple's documentation

Forums and blogs

Blog posts

Forums

Prominent figures

Podcasts

Summary

Index

Learning Swift

Copyright © 2015 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

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First published: June 2015

Production reference: 1250615

Published by Packt Publishing Ltd.

Livery Place

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Birmingham B3 2PB, UK.

ISBN 978-1-78439-250-5

www.packtpub.com

Credits

Author

Andrew J Wagner

Reviewers

Giordano Scalzo

Cory Bohon

Commissioning Editor

Sarah Crofton

Acquisition Editors

Vivek Anantharaman

Richard Brookes-Bland

Content Development Editor

Kirti Patil

Technical Editor

Mrunmayee Patil

Copy Editors

Pranjali Chury

Neha Vyas

Project Coordinator

Nidhi Joshi

Proofreader

Safis Editing

Indexer

Mariammal Chettiyar

Graphics

Disha Haria

Production Coordinator

Nilesh R. Mohite

Cover Work

Nilesh R. Mohite

About the Author

Andrew J Wagner is an independent software developer who concentrates on iOS development and backend web services and has a degree in computer engineering from Rensselaer Polytechnic Institute, New York. He has also been developing his own iOS apps through his company, Learn Brigade LLC, since 2008 and has experience working with and for large-scale companies and small-scale companies. He is passionate about using computers as a creative outlet and writing software that is beautiful in implementation, functionality, and experience.

About the Reviewer

Giordano Scalzo has been a developer since the days of the ZX Spectrum.

He wor...