Book Image

Object-Oriented JavaScript - Second Edition - Second Edition

Book Image

Object-Oriented JavaScript - Second Edition - 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
About the Authors
About the Reviewer
Built-in Functions
Regular Expressions


This is the second edition of the highly rated book Object-Oriented JavaScript by Stoyan Stefanov, Packt Publishing. After the release of the first edition, in the last five years, JavaScript has moved from being mostly used in browsers for client-side technologies to being used even on server side. This edition explores the "language side" of JavaScript. The stress is on the standards part of the language. The book talks about ECMA Script, Object-Oriented JS, patterns, prototypal inheritance, and design patterns.

The book doesn't assume any prior knowledge of JavaScript and works from the ground up to give you a thorough understanding of the language. People who know the language will still find it useful and informative. Exercises at the end of the chapters help you assess your understanding.

What this book covers

Chapter 1, Object-oriented JavaScript, talks briefly about the history, present, and future of JavaScript, and then moves on to explore the basics of object-oriented programming (OOP) in general. You then learn how to set up your training environment (Firebug) in order to dive into the language on your own, using the book examples as a base.

Chapter 2, Primitive Data Types, Arrays, Loops, and Conditions, discusses the language basics: variables, data types, primitive data types, arrays, loops, and conditionals.

Chapter 3, Functions, covers functions that JavaScript uses, and here you learn to master them all. You also learn about the scope of variables and JavaScript's built-in functions. An interesting, but often misunderstood feature of the language—closures—is demystified at the end of the chapter.

Chapter 4, Objects, talks about objects, how to work with properties and methods, and the various ways to create your objects. This chapter also talks about built-in objects such as Array, Function, Boolean, Number, and String.

Chapter 5, Prototype, is dedicated to the all-important concept of prototypes in JavaScript. It also explains how prototype chain works, hasOwnProperty(), and some gotchas of prototypes.

Chapter 6, Inheritance, discusses how inheritance works. This chapter also talks about a method to create subclasses like other classic languages.

Chapter 7, The Browser Environment, is dedicated to browsers. This chapter also covers BOM (Browser Object Model), DOM (W3C's Document Object Model), browser events, and AJAX.

Chapter 8, Coding and Design Patterns, dives into various unique JavaScript coding patterns, as well as several language-independent design patterns, translated to JavaScript from the Book of Four, the most influential work of software design patterns. The chapter also discusses JSON.

Appendix A, Reserved Words, lists the reserved words in JavaScript.

Appendix B, Built-in Functions, is a reference of built-in JavaScript functions together with sample uses.

Appendix C, Built-in Objects, is a reference that provides details and examples of the use of every method and property of every built-in object in JavaScript.

Appendix D, Regular Expressions, is a regular expressions pattern reference.

Appendix E, Answers to Exercise Questions, has solutions for all the exercises mentioned at the end of the chapters.

You can download this Appendix from

What you need for this book

You need a modern browser—Google Chrome or Firefox are recommended—and an optional Node.js setup. The latest version of Firefox comes with web developer tools, but Firebug is highly recommended. To edit JavaScript you can use any text editor of your choice.

Who this book is for

This book is for anyone who is starting to learn JavaScript or who knows JavaScript but isn't very good at the object-oriented part of it.


In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows: "If you want to be sure, you can check the cancellable property of the event object".

A block of code will be set as follows:

var a;
var thisIsAVariable;
var _and_this_too;
var mix12three;

When we wish to draw your attention to an output of a code block, the relevant lines or items will be shown in bold:

> var case_matters = 'lower';
> var CASE_MATTERS = 'upper';
> case_matters;

Any command-line input or output is written as follows:

alias jsc='/System/Library/Frameworks/JavaScriptCore.framework/Versions/Current/Resources/jsc'

New terms and important words are introduced in a bold-type font. Words that you see on the screen, in menus or dialog boxes for example, appear in our text like this: "If the user clicks on Cancel, the preventDefault() method is called".


Warnings or important notes appear in a box like this.


Tips and tricks appear like this.

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