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Mastering Swift 5.3

You're reading from   Mastering Swift 5.3 Upgrade your knowledge and become an expert in the latest version of the Swift programming language

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Product type Paperback
Published in Nov 2020
Publisher Packt
ISBN-13 9781800562158
Length 418 pages
Edition 6th Edition
Languages
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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 (23) Chapters Close

Preface 1. Taking the First Steps with Swift 2. Swift Documentation and Installing Swift FREE CHAPTER 3. Learning about Variables, Constants, Strings, and Operators 4. Optional Types 5. Using Swift Collections 6. Control Flow 7. Functions 8. Classes, Structures, and Protocols 9. Protocols and Protocol Extensions 10. Protocol-Oriented Design 11. Generics 12. Error Handling and Availability 13. Custom Subscripting 14. Working with Closures 15. Advanced and Custom Operators 16. Concurrency and Parallelism in Swift 17. Custom Value Types 18. Memory Management 19. Swift Formatting and Style Guide 20. Adopting Design Patterns in Swift 21. Other Books You May Enjoy
22. Index

Dictionaries

While dictionaries are not as commonly used as arrays, they have additional functionality that makes them incredibly powerful. A dictionary is a container that stores multiple key-value pairs, where all the keys are of the same type and all the values are of the same type. The key is used as a unique identifier for the value. A dictionary does not guarantee the order in which the key-value pairs are stored since we look up the values by key rather than by the index of the value.

Dictionaries are good for storing items that map to unique identifiers, where the unique identifier should be used to retrieve the item. Countries with their abbreviations are a good example of items that can be stored in a dictionary. In the following table, we show countries with their abbreviations as key-value pairs:

Key

Value

...
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