You're reading from Professional JavaScript for Web Developers Discover an easy-to-learn guide to upgrade your JavaScript skills

Product type Paperback

Published in Nov 2019

Publisher Wiley

ISBN-13 9781119366447

Length 1144 pages

Edition 4th Edition

Languages

JavaScript

Tools

Combine

Concepts

Web Programming

Author (1):

Matt Frisbie

View More author details

Table of Contents (37) Chapters

COVER FREE CHAPTER

FOREWORD

INTRODUCTION

1 What Is JavaScript?

2 JavaScript in HTML

3 Language Basics

4 Variables, Scope, and Memory

5 Basic Reference Types

6 Collection Reference Types

7 Iterators and Generators

8 Objects, Classes, and Object-Oriented Programming

9 Proxies and Reflect

10 Functions

11 Promises and Async Functions

12 The Browser Object Model

13 Client Detection

14 The Document Object Model

15 DOM Extensions

16 DOM Levels 2 and 3

17 Events

18 Animation and Graphics with Canvas

19 Scripting Forms

20 JavaScript APIs

21 Error Handling and Debugging

22 XML in JavaScript

23 JSON

24 Network Requests and Remote Resources

25 Client-Side Storage

26 Modules

27 Workers

28 Best Practices

A ES2018 and ES2019

B Strict Mode

C JavaScript Libraries and Frameworks

D JavaScript Tools

INDEX

END USER LICENSE AGREEMENT

WEB SOCKETS

The goal of Web Sockets is to provide full-duplex, bidirectional communication with the server over a single, long-lasting connection. When a Web Socket is created in JavaScript, an HTTP request is sent to the server to initiate a connection. When the server responds, the connection uses the HTTP Upgrade header to switch from HTTP to the Web Socket protocol. This means that Web Sockets cannot be implemented with a standard HTTP server and must use a specialized server supporting the protocol to work properly.

Because Web Sockets uses a custom protocol, the URL scheme is slightly different. Instead of using the http:// or https:// schemes, there are ws:// for an unsecured connection and wss:// for a secured connection. When specifying a Web Socket URL, you must include the scheme since other schemes may be supported in the future.

The advantage of using a custom protocol over HTTP is that very small amounts of data, unencumbered by the byte overhead of HTTP, can be sent between...