Book Image

Professional Scala

By : Mads Hartmann, Ruslan Shevchenko
Book Image

Professional Scala

By: Mads Hartmann, Ruslan Shevchenko

Overview of this book

This book teaches you how to build and contribute to Scala programs, recognizing common patterns and techniques used with the language. You’ll learn how to write concise, functional code with Scala. After an introduction to core concepts, syntax, and writing example applications with scalac, you’ll learn about the Scala Collections API and how the language handles type safety via static types out-of-the-box. You’ll then learn about advanced functional programming patterns, and how you can write your own Domain Specific Languages (DSLs). By the end of the book, you’ll be equipped with the skills you need to successfully build smart, efficient applications in Scala that can be compiled to the JVM.
Table of Contents (12 chapters)

Introduction to Functional Programming Concepts

In this section, we will cover the core concepts behind functional programming and give you the necessary knowledge to understand and write simple functional programs.

By the end of this section, you should have a good understanding of the core concepts behind functional programming, such as:

  • Writing and using pure functions

  • Using immutable classes instead of mutable classes

  • Writing and using higher-order functions

Pure Functions

At the very core of functional programming is the concept of a pure function. A function is pure if it doesn't have any side effects, that is, the function simply computes a result based on the arguments to the function and does nothing else.

Examples of side effects are modifying variables, setting fields on objects, performing input/output operations such as reading or writing a file, printing values to the console, and many more.

Let's look at some examples of both pure and impure functions to better understand...