Book Image

JavaScript : Functional Programming for JavaScript Developers

By : Ved Antani, Simon Timms, Dan Mantyla
Book Image

JavaScript : Functional Programming for JavaScript Developers

By: Ved Antani, Simon Timms, Dan Mantyla

Overview of this book

JavaScript is a high-level, dynamic, untyped, lightweight, and interpreted programming language and functional programming is a style that emphasizes and enables smarter code that minimizes complexity and increases modularity. It's a way of writing cleaner code through clever ways of mutating, combining, and using functions. And JavaScript provides an excellent medium for this approach. By learning how to expose JavaScript's true identity as a functional language, we can implement web apps that are more powerful, easier to maintain and more reliable. The java script: Functional Programming for JavaScript Developers course will take you on a journey to show how functional programming when combined with other techniques makes JavaScript programming more efficient. The first module Mastering JavaScript, stress on practical aspects of Javascript development like—Functions and Closures, Runtime debugging techniques, project layout, events and DOM processing, build tools, Object-oriented patterns, isomorphism—everything that a modern Javascript project would need. The second module, Mastering JavaScript Design Patterns - Second Edition, will explore how design patterns can help you improve and organize your JavaScript code. You’ll get to grips with creational, structural, and behavioral patterns as you discover how to put them to work in different scenarios. This updated edition will also delve into reactive design patterns and microservices as they are a growing phenomenon in the world of web development. It will also show you some advanced patterns, including dependency injection and live post processing. The third module, Functional Programming in JavaScript, will help you to write real-world applications by utilizing a wide range of functional techniques and styles. It explores the core concepts of functional programming common to all functional languages, with examples of their use in JavaScript.
Table of Contents (6 chapters)

Chapter 6. Functional Programming

Functional programming is a different approach to development than the heavily object oriented approach that we have focused on so far. Object oriented programming is a fantastic tool for solving a great number of problems but it has some issues. Parallel programming within an object oriented context is difficult as the state can be changed by various different threads with unknown side effects. Functional programming does not permit state or mutable variables. Functions act as primary building blocks in functional programming. Places where you might have used a variable in the past will now use a function.

Even in a single threaded program, functions can have side-effects that change global state. This means that, when calling an unknown function, it can alter the whole flow of the program. This makes debugging a program quite difficult.

JavaScript is not a functional programming language but we can still apply some functional principles to our...