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Mastering Swift 3

You're reading from   Mastering Swift 3 Build incredible apps for iOS and OS X

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Product type Paperback
Published in Oct 2016
Publisher Packt
ISBN-13 9781786466129
Length 392 pages
Edition 1st Edition
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Author (1):
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Jon Hoffman Jon Hoffman
Author Profile Icon Jon Hoffman
Jon Hoffman
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Table of Contents (18) Chapters Close

Preface 1. Taking the First Steps with Swift FREE CHAPTER 2. Learning About Variables, Constants, Strings, and Operators 3. Using Swift Collections and the Tuple Type 4. Control Flow and Functions 5. Classes and Structures 6. Using Protocols and Protocol Extensions 7. Protocol-Oriented Design 8. Writing Safer Code with Availability and Error Handling 9. Custom Subscripting 10. Using Optional Types 11. Working with Generics 12. Working with Closures 13. Using Mix and Match 14. Concurrency and Parallelism in Swift 15. Swift Formatting and Style Guide 16. Swifts Core Libraries 17. Adopting Design Patterns in Swift

Functions


In Swift, a function is a self-contained block of code that performs a specific task. Functions are generally used to logically break our code into reusable named blocks. The function's name is used to call the function.

When we define a function, we can also optionally define one or more parameters (also known as arguments). Parameters are named values that are passed into the function by the code that calls it. These parameters are generally used within the function to perform the task of the function. We can also define default values for the parameters to simplify how the function is called.

Every Swift function has a type associated with it. This type is referred to as the return type and it defines the type of data returned from the function to the code that called it. If a value is not returned from a function, the return type is Void.

Let's look at how to define functions in Swift.

Using a single parameter function

The syntax used to define a function in Swift is very flexible...

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