Apple announced Swift at WWDC 2014 as a new programming language that combines experience with the Objective-C platform and advances in dynamic and statically typed languages over the last few decades. Before Swift, most code written for iOS and OS X applications was in Objective-C, a set of object-oriented extensions to the C programming language. Swift aims to build upon patterns and frameworks of Objective-C but with a more modern runtime and automatic memory management. In December 2015, Apple open sourced Swift at https://swift.org and made binaries available for Linux as well as OS X. The content in this chapter can be run on either Linux or OS X, but the remainder of the book is either Xcode-specific or depends on iOS frameworks that are not open source. Developing iOS applications requires Xcode and OS X.
This chapter will present the following topics:
How to use the Swift REPL to evaluate Swift code
The different types of Swift literals
How to use arrays and dictionaries
Functions and the different types of function arguments
Compiling and running Swift from the command line