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Learning Swift Second Edition

Learning Swift Second Edition

By : Andrew J Wagner
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Learning Swift Second Edition

Learning Swift Second Edition

5 (1)
By: Andrew J Wagner

Overview of this book

Swift is Apple’s new programming language and the future of iOS and OS X app development. It is a high-performance language that feels like a modern scripting language. On the surface, Swift is easy to jump into, but it has complex underpinnings that are critical to becoming proficient at turning an idea into reality. This book is an approachable, step-by-step introduction into programming with Swift for everyone. It begins by giving you an overview of the key features through practical examples and progresses to more advanced topics that help differentiate the proficient developers from the mediocre ones. It covers important concepts such as Variables, Optionals, Closures, Generics, and Memory Management. Mixed in with those concepts, it also helps you learn the art of programming such as maintainability, useful design patterns, and resources to further your knowledge. This all culminates in writing a basic iOS app that will get you well on your way to turning your own app ideas into reality.
Table of Contents (14 chapters)
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13
Index

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Now that we understand the different ways in which data is represented in Swift, we can look into how we can manage the memory better. Every instance that we create takes up memory. Naturally, it wouldn't make sense to keep all data around forever. Swift needs to be able to free up memory so that it can be used for other purposes, once our program doesn't need it anymore. This is the key to managing memory in our apps. We need to make sure that Swift can free up all the memory that we no longer need, as soon as possible.

The way that Swift knows it can free up memory is when the code can no longer access an instance. If there is no longer any variable or constant referencing an instance, it can be repurposed for another instance. This is called "freeing the memory" or "deleting the object".

In Chapter 3, One Piece at a Time – Types, Scopes, and Projects we already discussed when a variable is accessible or not in the section about scopes. This makes memory management...

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