Swift is a language so new that even most programming experts have barely a few months of experience in it. However, it borrows most of its features from several other programming languages, such as Ruby, Python Scala, Rust, Groovy, and even JavaScript and Haskell. So, anyone who approaches Swift will already feel at home, recognizing the patterns and features of their favorite programming languages.

Moreover, unlike Objective-C, whose learning curve is really steep for beginners, Swift is really friendly for newcomers, who can write code once they learn the basics of the language.

Nevertheless, mastering Swift when using its more advanced features, such as effectively integrating patterns of functional programming with object-oriented concepts, takes time, and most best practices still need to be discovered.

Also, Swift's language is just one part of the story. A lone language without an environment where it can build something is just a sterile exercise. Swift is not a general-purpose language, but a language with a specific goal—building apps for iOS and OS X using the Cocoa framework.

It's in this framework that the complexity resides; Cocoa is a very big framework, with thousands of APIs and different patterns and best practices. It has changed significantly over the course of its several releases, for example, moving from the delegate pattern to the use of blocks to make components interact with loose coupling.

More than knowing the language, the real challenge is in knowing the framework. I want to stress that the aim of this chapter is just to help you get the first grasp of what Swift's constructs look like, and not to be exhaustive, so expect to find a certain degree of simplification. Also, be aware that a deeper knowledge of the language can be achieved with books that specialize only in Swift learning, whereas the goal of this book is to teach you how to build apps using Swift.