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

PRIMITIVE AND REFERENCE VALUES

ECMAScript variables may contain two different types of data: primitive values and reference values. Primitive values are simple atomic pieces of data, while reference values are objects that may be made up of multiple values.

When a value is assigned to a variable, the JavaScript engine must determine if it's a primitive or a reference value. The six primitive types were discussed in the previous chapter: Undefined, Null, Boolean, Number, String, and Symbol. These variables are said to be accessed by value, because you are manipulating the actual value stored in the variable.

Reference values are objects stored in memory. Unlike other languages, JavaScript does not permit direct access of memory locations, so direct manipulation of the object's memory space is not allowed. When you manipulate an object, you're really working on a reference to that object rather than the actual object itself. For this reason, such values are said to...