Book excerpt: 'Swift for Programmers' is a programming-language focused book designed to get practicing programmers up-to-speed quickly in Swift programming. The Deitels provide thousands of lines of proven Swift code in the book, using a mix of code snippets and live-code examples. When they present code snippets rather than full-length complete programs, the snippet will be extracted from a Deitel-created, compiled, live-code example to ensure that the snippet is correct