Book Image

Object-Oriented JavaScript - Second Edition

Book Image

Object-Oriented JavaScript - Second Edition

Overview of this book

JavaScript is the behavior, the third pillar in today's paradigm that looks at web pages as something that consists of clearly distinguishable parts: content (HTML), presentation (CSS) and behavior (JavaScript). Using JavaScript, you can create not only web pages but also desktop widgets, browser and application extensions, and other pieces of software. It's a pretty good deal: you learn one language and then code all kinds of different applications. While there's one chapter specifically dedicated to the web browser environment including DOM, Events and AJAX tutorials, the rest is applicable to the other environments Many web developers have tried coding or adopting some bits of JavaScript, but it is time to "man up" and learn the language properly because it is the language of the browser and is, virtually, everywhere. This book starts from zero, not assuming any prior JavaScript programming knowledge and takes you through all the in-depth and exciting futures hidden behind the facade. Once listed in the "nice to have" sections of job postings, these days the knowledge of JavaScript is a deciding factor when it comes to hiring web developers. After reading this book you'll be prepared to ace your JavaScript job interview and even impress with some bits that the interviewer maybe didn't know. You should read this book if you want to be able to take your JavaScript skills to a new level of sophistication.
Table of Contents (19 chapters)
Object-Oriented JavaScript Second Edition
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Built-in Functions
Regular Expressions
Index

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 is created, called a prototype chain:

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 to know...