Book Image

Object-Oriented JavaScript - Third Edition

By : Ved Antani, Stoyan STEFANOV
5 (1)
Book Image

Object-Oriented JavaScript - Third Edition

5 (1)
By: Ved Antani, Stoyan STEFANOV

Overview of this book

JavaScript is an object-oriented programming language that is used for website development. Web pages developed today currently follow a paradigm that has three clearly distinguishable parts: content (HTML), presentation (CSS), and behavior (JavaScript). JavaScript is one important pillar in this paradigm, and is responsible for the running of the web pages. This book will take your JavaScript skills to a new level of sophistication and get you prepared for your journey through professional web development. Updated for ES6, this book covers everything you will need to unleash the power of object-oriented programming in JavaScript while building professional web applications. The book begins with the basics of object-oriented programming in JavaScript and then gradually progresses to cover functions, objects, and prototypes, and how these concepts can be used to make your programs cleaner, more maintainable, faster, and compatible with other programs/libraries. By the end of the book, you will have learned how to incorporate object-oriented programming in your web development workflow to build professional JavaScript applications.
Table of Contents (25 chapters)
Object-Oriented JavaScript - Third Edition
About the Authors
About the Reviewer
Customer Feedback
Built-in Functions
Regular Expressions


ES6 introduces four data structures-Map, WeakMap, Set, and WeakSet. JavaScript, when compared to other languages such as Python and Ruby, had a very weak standard library to support hash or Map data structures or dictionaries. Several hacks were invented to somehow achieve the behavior of a Map by mapping a string key with an object. There were side effects of such hacks. Language support for such data structures was sorely needed.

ES6 supports standard dictionary data structures; we will look at more details around these in the next section.


Map allows arbitrary values as keys. The keys are mapped to values. Maps allow fast access to values. Let's look at some examples of maps:

    const m = new Map(); //Creates an empty Map 
    m.set('first', 1);   //Set a value associated with a key 
    console.log(m.get('first'));  //Get a value using the key 

We will create an empty Map using the constructor. You can use the set() method to add an entry to the Map associating...