Swift is a programming language developed by Apple primarily to allow developers to continue to push their platforms forward. It is their attempt to make iOS, OS X, watchOS, and tvOS app development more modern, safe, and powerful.

However, Apple has also released Swift as Open Source and begun an effort to add support for Linux with the intent to make Swift even better and a general purpose programming language available everywhere. Some developers have already begun using it to create command-line scripts as a replacement/supplement of the existing scripting languages, such as Python or Ruby and many can't wait to be able to share some of their app code with Web backend code. Apple's priority, at least for now, is to make it the best language possible, to facilitate app development. However, the most important thing to remember is that modern app development almost always requires pulling together multiple platforms into a single-user experience. If a language could bridge those gaps and stay enjoyable to write, safe, and performant, we would have a much easier time making amazing products. Swift is well on its way to reach that goal.

Now, it is important to note that learning Swift is only the first step towards developing. To develop for a device, you must learn the programming language and the frameworks the device maker provides. Being skilled with a programming language is the foundation of getting better at using frameworks and ultimately building apps.

Developing software is like building a table. You can learn the basics of woodworking and nail a few pieces of wood together to make a functional table, but you are very limited in what you can do because you lack advanced woodworking skills. If you want to make a truly great table, you need to step away from the table and focus first on developing your skill set. The better you are at using the tools, the greater the number of possibilities that open up to you to create a more advanced and higher quality piece of furniture. Similarly, with a very limited knowledge of Swift, you can start to piece together a functional app from the code you find online. However, to really make something great, you have to put the time and effort into refining your skill set with the language. Every language feature or technique that you learn opens up more possibilities for your app.

That being said, most developers are driven by a passion to create things and solve problems. We learn best when we can channel our passions into truly improving ourselves and the world around us. We don't want to get stuck learning the minutia of a language with no practical purpose.

The goal of this book is to develop your skills and confidence to dive passionately into creating compelling, maintainable, and elegant apps in Swift. To do that, we will introduce the syntax and features of Swift in a practical way. You will build a rich toolset, while seeing that toolset put to real world usage. So, without further ado, let's jump right into setting up our development environment.