A number of resources are available for learning to program with Swift. While the focus of this book is primarily on the tools, libraries, and runtimes needed to create Swift applications on the server, this chapter will start off with a background and overview of the Swift language.
The Swift programming language was first announced to the public by Apple at their World Wide Developers Conference in 2014. At that time, Apple developers were writing their applications solely in the Objective-C language, which was first released back in 1984. This was a big deal. Swift offered the potential for better performance and improved application security and stability, along with a host of modern language features. Swift provided easy interoperability with existing C and Objective-C libraries, while also offering fresh, modern language capabilities such as type-inference, generics, enumerated types, first-class functions, some functional language capabilities, and more. The result was a language that was fun to program with its extensibility and concise syntax (similar to some scripting languages), while also offering the safety and performance of a strongly typed, compiled language.
In the past two years since its release, Swift has gone through a number of versions as it has matured. With the release of Swift 3.0 in September 2016, the language has reached a new level of source stability. I would encourage you to learn the new language ...