Mastering JavaScript

Ved Antani

• Publisher: Packt Publishing
• Year: 2016
• eBook ISBN: 9781785281341
• Edition: 1
• Topic: Computer Science
• Subtopic: Programming in JavaScript
• Index: Computer Science

Explore and master modern JavaScript techniques in order to build large-scale web applications

About This Book

• Write powerful code with the high-level functions that JavaScript offers
• Test and debug issues with JavaScript code using various modern mechanisms
• Offers an expert's eye on the latest ES6 features and how these advanced tasks fit together in JavaScript as a whole

Who This Book Is For

This book is ideal for web developers who are looking to master modern JavaScript concepts and design principles. You should already have an intermediate level of JavaScript knowledge before starting this book.

What You Will Learn

• Get a run through of the basic JavaScript language constructs
• Get familiar with the Functions and Closures of JavaScript
• Explore Regular Expressions in JavaScript
• Code using the powerful object-oriented feature in JavaScript
• Test and debug your code using JavaScript strategies
• Master DOM manipulation, cross-browser strategies, and ES6
• Understand the basic concurrency constructs in Javascript and best performance strategies
• Learn to build scalable server application in JavaScript using Node.js

In Detail

JavaScript is a high-level, dynamic, untyped, lightweight, and interpreted programming language. Along with HTML and CSS, it is one of the three essential technologies of World Wide Web content production, and is an open source and cross-platform technology. The majority of websites employ JavaScript, and it is well supported by all modern web browsers without plugins. However, the JavaScript landscape has changed dramatically in recent years, and you need to adapt to the new world of JavaScript that people now expect. Mastering modern JavaScript techniques and the toolchain are essential to develop web-scale applications.

Mastering JavaScript will be your companion as you master JavaScript and build innovative web applications. To begin with, you will get familiarized with the language constructs and how to make code easy to organize. You will gain a concrete understanding of variable scoping, loops, and best practices on using types and data structures, as well as the coding style and recommended code organization patterns in JavaScript. The book will also teach you how to use arrays and objects as data structures. You will graduate from intermediate-level skills to advanced techniques as you come to understand crucial language concepts and design principles. You will learn about modern libraries and tools so you can write better code.

By the end of the book, you will understand how reactive JavaScript is going to be the new paradigm.

Style and approach

This is a comprehensive guide with a clear focus on practical use cases and patterns. Each chapter consists of best practices, useful advice, and a bunch of easy-to-follow examples that will build up your skills as you advance through the book.

Mastering JavaScript

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Table of Contents

Mastering JavaScript

Credits

About the Author

About the Reviewer

www.PacktPub.com

Support files, eBooks, discount offers, and more

Why subscribe?

Free access for Packt account holders

Preface

What this book covers

What you need for this book

Who this book is for

Conventions

Reader feedback

Customer support

Downloading the example code

Downloading the color images of this book

Errata

Piracy

Questions

1. JavaScript Primer

A little bit of history

How to use this book

Hello World

An overview of JavaScript

Comments

Variables

Constants

Number

String

Undefined values

Booleans

The instanceof operator

Date objects

The + operator

The ++ and -- operators

Boolean operators

Equality

Strict equality using ===

Weak equality using ==

JavaScript types

Automatic semicolon insertion

JavaScript style guide

Whitespaces

Parentheses, line breaks, and braces

Quotes

End of lines and empty lines

Type checking

Type casting

Conditional evaluation

Naming

The eval() method is evil

The strict mode

Enabling the strict mode for an existing code can break it

Package with care

Variables must be declared in strict mode

The eval() function is cleaner in strict mode

Features that are blocked in strict mode

Running JSHint

Summary

2. Functions, Closures, and Modules

A function literal

A function declaration

Functions as data

Scoping

Global scope

Local scope

Function-level scope versus block-level scope

Inline function expressions

Block scopes

Function declarations versus function expressions

The arguments parameter

The this parameter

Invocation as a function

Invocation as a method

Invocation as a constructor

Invocation using apply() and call() methods

Anonymous functions

Anonymous functions while creating an object

Anonymous functions while creating a list

Anonymous functions as a parameter to another function

Anonymous functions in conditional logic

Closures

Timers and callbacks

Private variables

Loops and closures

Modules

Stylistic considerations

Summary

3. Data Structures and Manipulation

Regular expressions

Exact match

Match from a class of characters

Repeated occurrences

Alternatives – OR

Beginning and end

Backreferences

Greedy and lazy quantifiers

Arrays

Maps

Sets

A matter of style

Summary

4. Object-Oriented JavaScript

Understanding objects

Behavior of JavaScript objects

Prototypes

Instance properties versus prototype properties

Inheritance

Getters and setters

Summary

5. JavaScript Patterns

Design patterns

The namespace pattern

The module pattern

ES6 modules

The factory pattern

The mixin pattern

The decorator pattern

The observer pattern

JavaScript Model-View-* patterns

Model-View-Controller

Models

Views

Controllers

The Model-View-Presenter pattern

Model-View-ViewModel

Summary

6. Testing and Debugging

Unit testing

Test-driven development

Behavior-driven development

JavaScript debugging

Syntax errors

Using strict

Runtime exceptions

Console.log and asserts

Chrome DevTools

Summary

7. ECMAScript 6

Shims or polyfills

Transpilers

ES6 syntax changes

Block scoping

Default parameters

Spread and rest

Destructuring

Object literals

Template literals

Maps and Sets

Symbols

Iterators

For..of loops

Arrow functions

Summary

8. DOM Manipulation and Events

DOM

Accessing DOM elements

Accessing specific nodes

Chaining

Traversal and manipulation

Working with browser events

Propagation

jQuery event handling and propagation

Event delegation

The event object

Summary

9. Server-Side JavaScript

An asynchronous evented-model in a browser

Callbacks

Timers

EventEmitters

Modules

Creating modules

npm

Installing packages

JavaScript performance

JavaScript profiling

The CPU profile

The Timeline view

Summary

Index

Mastering JavaScript

Copyright © 2016 Packt Publishing

All rights reserved. No part of this book may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, without the prior written permission of the publisher, except in the case of brief quotations embedded in critical articles or reviews.

Every effort has been made in the preparation of this book to ensure the accuracy of the information presented. However, the information contained in this book is sold without warranty, either express or implied. Neither the author, nor Packt Publishing, and its dealers and distributors will be held liable for any damages caused or alleged to be caused directly or indirectly by this book.

Packt Publishing has endeavored to provide trademark information about all of the companies and products mentioned in this book by the appropriate use of capitals. However, Packt Publishing cannot guarantee the accuracy of this information.

First published: January 2016

Production reference: 1250116

Published by Packt Publishing Ltd.

Livery Place

35 Livery Street

Birmingham B3 2PB, UK.

ISBN 978-1-78528-134-1

www.packtpub.com

Credits

Author

Ved Antani

Reviewer

Ivano Malavolta

Commissioning Editor

Sarah Crofton

Acquisition Editor

Kevin Colaco

Content Development Editor

Merint Mathew

Technical Editor

Manthan Raja

Copy Editor

Tasneem Fatehi

Project Coordinator

Francina Pinto

Proofreader

Safis Editing

Indexer

Monica Ajmera Mehta

Production Coordinator

Conidon Miranda

Cover Work

Conidon Miranda

About the Author

Ved Antani is an AVP (engineering) at Myntra. Before Myntra, he worked with Electronic Arts, NetApp, and Oracle. Ved is passionate about programming and has been programming in JavaScript since 2005. He has extensive experience in building scalable systems and mobile applications. Ved is a minimalist, a father, and an avid tea drinker.

I would like to thank my wife, Meghna, for her support. She was always there to encourage and help me when I needed it the most.

About the Reviewer

Ivano Malavolta is a postdoctoral researcher at the Gran Sasso Science Institute (L'Aquila, Italy), and he holds a PhD in computer science from the University of L'Aquila. His research is positioned in three main fields: software architecture, Model-Driven Engineering (MDE), and mobile-enabled systems. He is especially interested in investigating how MDE techniques can be exploited for architecting complex and mobile-enabled software systems at the right level of abstraction. He is the author of more than 40 papers in international journals and peer-reviewed international conferences' proceedings; among them, he has coauthored two articles published in the IEEE Transactions on Software Engineering (TSE), which is considered the leading journal in the field...

Table of contents

• Mastering JavaScript