Book Image

Mastering JavaScript Functional Programming

By : Federico Kereki
Book Image

Mastering JavaScript Functional Programming

By: Federico Kereki

Overview of this book

Functional programming is a programming paradigm for developing software using functions. Learning to use functional programming is a good way to write more concise code, with greater concurrency and performance. The JavaScript language is particularly suited to functional programming. This book provides comprehensive coverage of the major topics in functional programming with JavaScript to produce shorter, clearer, and testable programs. You’ll delve into functional programming; including writing and testing pure functions, reducing side-effects, and other features to make your applications functional in nature. Specifically, we’ll explore techniques to simplify coding, apply recursion for loopless coding, learn ways to achieve immutability, implement design patterns, and work with data types. By the end of this book, you’ll have developed the JavaScript skills you need to program functional applications with confidence.
Table of Contents (22 chapters)
Title Page
About the Author
About the Reviewer
Customer Feedback
Connecting Functions - Pipelining and Composition
Answers to Questions

Data types

Even though JavaScript is a dynamic language, without static or explicit typing declarations and controls, it doesn't mean that you can simply ignore types. Even if the language doesn't allow you to specify the types of your variables or functions, you still work --even if only in your head-- with types. Let's now get into the theme of seeing how we can specify types, for that we will have at least some advantages:

  • Even if you don't have runtime data type checking, there are several tools, such as Facebook's flow static type checker or Microsoft's TypeScript language, which let you deal with it
  • It will help if you plan to move on from JavaScript to a more functional language such as Elm
  • It serves as documentation, to let future developers understand what type of arguments they have to pass to the function, and what type it will return. As an example of this, all the functions in the Ramda library are documented in this way
  • It will also help with the functional data structures later...