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 5. Behavioral Patterns

In the last chapter we looked at structural patterns that describe ways in which objects can be constructed to ease interaction.

In this chapter we'll take a look at the final, and largest, grouping of GoF patterns: behavioral patterns. These patterns are ones that provide guidance on how objects share data or, from a different perspective, how data flows between objects.

The patterns we'll look at are as follows:

  • Chain of responsibility
  • Command
  • Interpreter
  • Iterator
  • Mediator
  • Memento
  • Observer
  • State
  • Strategy
  • Template method
  • Visitor

Once again there are a number of more recently identified patterns that could well be classified as behavioral patterns. We'll defer looking at those until a later chapter, instead keeping to the GoF patterns.

Chain of responsibility

We can think of a function call on an object as sending that object a message. Indeed this message passing mentality is one that dates back to the days of Smalltalk. The chain of responsibility...