Browse Library
Sign In Start Free Trial
Close icon Search icon
Account
Browse Library Advanced Search Sign In Start Free Trial

Add to playlist

Create a Playlist

Modal Close icon
You need to login to use this feature.
  • Book Overview & Buying Learning Swift
  • Table Of Contents Toc
  • Feedback & Rating feedback
Learning Swift

Learning Swift

By : Andrew J Wagner
4.8 (5)
Buy this Book
close
close
Learning Swift

Learning Swift

4.8 (5)
By: Andrew J Wagner
Buy this Book

Overview of this book

If you are looking to build iOS or OS X apps using the most modern technology, this book is ideal for you. You will find this book especially useful if you are new to programming or if you have yet to develop for iOS or OS X.
Table of Contents (13 chapters)
close
close
close
Preface
Preface
What this book covers
What you need for this book
Who this book is for
Conventions
Reader feedback
Customer support
Free Chapter
1
1. Introducing Swift
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
2. Building Blocks – Variables, Collections, and Flow Control
2. Building Blocks – Variables, Collections, and Flow Control
Core Swift types
Swift's type system
Printing on the console
Control flow
Functions
Bringing it all together
Summary
3
3. One Piece at a Time – Types, Scopes, and Projects
3. One Piece at a Time – Types, Scopes, and Projects
Structs
Classes
Enumerations
Projects
Extensions
Scope
Access control
Summary
4
4. To Be or Not to Be – Optionals
4. To Be or Not to Be – Optionals
Introducing optionals
Unwrapping an optional
Optional chaining
Implicitly unwrapped optionals
Debugging optionals
The underlying implementation
Summary
5
5. A Modern Paradigm – Closures and Functional Programming
5. A Modern Paradigm – Closures and Functional Programming
Functional programming philosophy
Closures
Building blocks of functional programming in Swift
Lazy evaluation
Curried functions
Summary
6
6. Make Swift Work for You – Protocols and Generics
chevron up
6. Make Swift Work for You – Protocols and Generics
Protocols
Defining a generic
Extending the existing generics
Putting protocols and generics to use
Summary
7
7. Everything is Connected – Memory Management
7. Everything is Connected – Memory Management
How data is stored in a computer
Value types versus reference types
Automatic reference counting
Strong reference cycles
Lost objects
Summary
8
8. Writing Code the Swift Way – Design Patterns and Techniques
8. Writing Code the Swift Way – Design Patterns and Techniques
What is a design pattern?
Behavioral patterns
Structural patterns
Creational patterns
Using associated values effectively
Extending system types to reduce code
Lazy properties
Summary
9
9. Harnessing the Past – Understanding and Translating Objective-C
9. Harnessing the Past – Understanding and Translating Objective-C
Swift's relationship with Objective-C
The history of Objective-C
Constants and variables
Containers
Control flow
Functions
Types
Projects
Calling Objective-C code from Swift
Using functions
Summary
10
10. A Whole New World – Developing an App
10. A Whole New World – Developing an App
Conceptualizing the app
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
11. What's Next? Resources, Advice, and Next Steps
11. What's Next? Resources, Advice, and Next Steps
Apple's documentation
Forums and blogs
Prominent figures
Podcasts
Summary
12
Index
Index

Defining a generic

A generic is very similar to a type alias. The difference is that the exact type of a generic is determined by the context in which it is used, instead of the implementing types. This also means that a generic only has a single implementation that must support all of the possible types. Let's start by defining a generic function.

The generic function

In Chapter 5, A Modern Paradigm – Closures and Functional Programming, we created a function that helped us find the first number in an array of numbers that passes a test:

func firstInNumbers(
    numbers: [Int],
    passingTest: (number: Int) -> Bool
    ) -> Int?
{
    for number in numbers {
        if passingTest(number: number) {
            return number
        }
    }
    return nil
}

This would be great if we only ever deal with arrays of the Int types, but clearly, it would be helpful if we are able to do this with other types. In fact, I dare say, it would be helpful for all types. We can achieve this very simply...

Unlock full access

Continue reading for free

A Packt free trial gives you instant online access to our library of over 7000 practical eBooks and videos, constantly updated with the latest in tech
Start a 7-day FREE trial
End of Section 4
Next Section
bookmark search playlist font-size

Change the font size

margin-width

Change margin width

day-mode

Change background colour

Close icon Search
Country selected
Close icon Your notes and bookmarks

Delete Bookmark

Modal Close icon
Are you sure you want to delete it?
Cancel
Yes, Delete

Confirmation

Modal Close icon
claim successful
Order Page Read Now

Buy this book with your credits?

Modal Close icon
Are you sure you want to buy this book with one of your credits?
Close
YES, BUY