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

Prototype chaining

Let's start with the default way of implementing inheritance - inheritance chaining through the prototype.

As you already know, every function has a prototype property, which points to an object. When a function is invoked using the new operator, an object is created and returned. This new object has a secret link to the prototype object. The secret link (called __proto__ in some environments) allows methods and properties of the prototype object to be used as if they belonged to the newly created object.

The prototype object is just a regular object and, therefore, it also has the secret link to its prototype. And so, a chain called a prototype chain is created:

In this illustration, an object A contains a number of properties. One of the properties is the hidden __proto__ property, which points to another object, B. B's __proto__ property points to C. This chain ends with the Object.prototype object, the grandparent, and every object inherits from it.

This is all good...