JavaScript: The Definitive Guide: Master the World's Most-Used Programming Language. 7 Ed

Preface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
1. Introduction to JavaScript. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Exploring JavaScript 3
1.2 Hello World 5
1.3 A Tour of JavaScript 5
1.4 Example: Character Frequency Histograms 11
1.5 Summary 14
2. Lexical Structure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1 The Text of a JavaScript Program 15
2.2 Comments 16
2.3 Literals 16
2.4 Identifiers and Reserved Words 16
2.5 Unicode 17
2.6 Optional Semicolons 19
2.7 Summary 21
3. Types, Values, and Variables. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3.1 Overview and Definitions 23
3.2 Numbers 25
3.3 Text 32
3.4 Boolean Values 38
3.5 null and undefined 40
3.6 Symbols 41
3.7 The Global Object 42
3.8 Immutable Primitive Values and Mutable Object References 43
3.9 Type Conversions 45
3.10 Variable Declaration and Assignment 53
3.11 Summary 60
4. Expressions and Operators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.1 Primary Expressions 62
4.2 Object and Array Initializers 62
4.3 Function Definition Expressions 63
4.4 Property Access Expressions 64
4.5 Invocation Expressions 66
4.6 Object Creation Expressions 68
4.7 Operator Overview 68
4.8 Arithmetic Expressions 73
4.9 Relational Expressions 78
4.10 Logical Expressions 84
4.11 Assignment Expressions 86
4.12 Evaluation Expressions 88
4.13 Miscellaneous Operators 91
4.14 Summary 96
5. Statements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
5.1 Expression Statements 98
5.2 Compound and Empty Statements 99
5.3 Conditionals 100
5.4 Loops 105
5.5 Jumps 112
5.6 Miscellaneous Statements 121
5.7 Declarations 124
5.8 Summary of JavaScript Statements 127
6. Objects. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
6.1 Introduction to Objects 129
6.2 Creating Objects 130
6.3 Querying and Setting Properties 133
6.4 Deleting Properties 138
6.5 Testing Properties 139
6.6 Enumerating Properties 140
6.7 Extending Objects 142
6.8 Serializing Objects 143
6.9 Object Methods 144
6.10 Extended Object Literal Syntax 146
6.11 Summary 153
7. Arrays. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
7.1 Creating Arrays 156
7.2 Reading and Writing Array Elements 159
7.3 Sparse Arrays 160
7.4 Array Length 161
7.5 Adding and Deleting Array Elements 161
7.6 Iterating Arrays 162
7.7 Multidimensional Arrays 164
7.8 Array Methods 165
7.9 Array-Like Objects 177
7.10 Strings as Arrays 179
7.11 Summary 180
8. Functions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181
8.1 Defining Functions 182
8.2 Invoking Functions 186
8.3 Function Arguments and Parameters 193
8.4 Functions as Values 200
8.5 Functions as Namespaces 203
8.6 Closures 204
8.7 Function Properties, Methods, and Constructor 209
8.8 Functional Programming 213
8.9 Summary 219
9. Classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
9.1 Classes and Prototypes 222
9.2 Classes and Constructors 224
9.3 Classes with the class Keyword 229
9.4 Adding Methods to Existing Classes 236
9.5 Subclasses 237
9.6 Summary 248
10. Modules. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
10.1 Modules with Classes, Objects, and Closures 250
10.2 Modules in Node 253
10.3 Modules in ES6 255
10.4 Summary 266
11. The JavaScript Standard Library. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
11.1 Sets and Maps 268
11.2 Typed Arrays and Binary Data 275
11.3 Pattern Matching with Regular Expressions 281
11.4 Dates and Times 300
11.5 Error Classes 304
11.6 JSON Serialization and Parsing 306
11.7 The Internationalization API 309
11.8 The Console API 317
11.9 URL APIs 320
11.10 Timers 323
11.11 Summary 325
12. Iterators and Generators. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
12.1 How Iterators Work 328
12.2 Implementing Iterable Objects 329
12.3 Generators 332
12.4 Advanced Generator Features 336
12.5 Summary 339
13. Asynchronous JavaScript. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
13.1 Asynchronous Programming with Callbacks 342
13.2 Promises 346
13.3 async and await 367
13.4 Asynchronous Iteration 370
13.5 Summary 377
14. Metaprogramming. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
14.1 Property Attributes 380
14.2 Object Extensibility 384
14.3 The prototype Attribute 386
14.4 Well-Known Symbols 387
14.5 Template Tags 395
14.6 The Reflect API 397
14.7 Proxy Objects 399
14.8 Summary 406
15. JavaScript in Web Browsers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409
15.1 Web Programming Basics 411
15.2 Events 426
15.3 Scripting Documents 437
15.4 Scripting CSS 452
15.5 Document Geometry and Scrolling 459
15.6 Web Components 464
15.7 SVG: Scalable Vector Graphics 477
15.8 Graphics in a <canvas> 484
15.9 Audio APIs 507
15.10 Location, Navigation, and History 509
15.11 Networking 518
15.12 Storage 536
15.13 Worker Threads and Messaging 548
15.14 Example: The Mandelbrot Set 555
15.15 Summary and Suggestions for Further Reading 568
16. Server-Side JavaScript with Node. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 577
16.1 Node Programming Basics 578
16.2 Node Is Asynchronous by Default 583
16.3 Buffers 586
16.4 Events and EventEmitter 588
16.5 Streams 590
16.6 Process, CPU, and Operating System Details 601
16.7 Working with Files 602
16.8 HTTP Clients and Servers 613
16.9 Non-HTTP Network Servers and Clients 617
16.10 Working with Child Processes 620
16.11 Worker Threads 625
16.12 Summary 634
17. JavaScript Tools and Extensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 635
17.1 Linting with ESLint 636
17.2 JavaScript Formatting with Prettier 637
17.3 Unit Testing with Jest 638
17.4 Package Management with npm 640
17.5 Code Bundling 642
17.6 Transpilation with Babel 644
17.7 JSX: Markup Expressions in JavaScript 645
17.8 Type Checking with Flow 649
17.9 Summary 665
Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 667

JavaScript is the programming language of the web and is used by more software developers today than any other programming language. For nearly 25 years this best seller has been the go-to guide for JavaScript programmers. The seventh edition is fully updated to cover the 2020 version of JavaScript, and new chapters cover classes, modules, iterators, generators, Promises, async/await, and metaprogramming. You’ll find illuminating and engaging example code throughout.

This book is for programmers who want to learn JavaScript and for web developers who want to take their understanding and mastery to the next level. It begins by explaining the JavaScript language itself, in detail, from the bottom up. It then builds on that foundation to cover the web platform and Node.js.

Topics include:

• Types, values, variables, expressions, operators, statements, objects, and arrays

• Functions, classes, modules, iterators, generators, Promises, and async/await

• JavaScript’s standard library: data structures, regular expressions, JSON, i18n, etc.

• The web platform: documents, components, graphics, networking, storage, and threads

• Node.js: buffers, files, streams, threads, child processes, web clients, and web servers

• Tools and language extensions that professional JavaScript developers rely on