Functional Programming in Scala, Second Edition

Part 1. Introduction to functional programming

We begin this book with a radical and restrictive premise: we will be constructing programs using only pure functions with no side effects, such as reading from files or mutating memory. This idea, of FP, leads to a very different way of writing programs than you may be used to. We therefore start from the very beginning, relearning how to write the simplest of programs in a functional way.

In the first chapter, we’ll explain exactly what FP means and give you some idea of its benefits. The rest of the chapters in part 1 introduce the basic techniques for functional programming in Scala. Chapter 2 introduces the Scala language and covers fundamentals, including writing loops functionally and manipulating ...