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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Sprache: Englisch
All of JavaScript's newest features, in depth, made easy to understand. JavaScript is a rapidly changing language and it can be challenging to keep up with all the new toys being added. JavaScript: The New Toys explores the newest features of the world's most popular programming language while also showing readers how to track what's coming next. After setting the stage by covering who manages the process of improving JavaScript, how new features get introduced, terminology, and a high-level overview of new features, it details each new or updated item in depth, with example uses, possible pitfalls, and expert recommendations for updating old habits in light of new features. JavaScript: The New Toys: * Covers all the additions to JavaScript in ES2015-ES2020 plus a preview of what's coming next * Explores the latest syntax: nullish coalescing, optional chaining, let and const, class syntax, private methods, private fields, new.target, numeric separators, BigInt, destructuring, default parameters, arrow functions, async functions, await, generator functions, ... (rest and spread), template literals, binary and octal literals, ** (exponentiation), computed property/method names, for-of, for-await-of, shorthand properties, and others * Details the new features and patterns including modules, promises, iteration, generators, Symbol, Proxy, reflection, typed arrays, Atomics, shared memory, WeakMap, WeakSet, and more * Highlights common pitfalls and explains how to avoid them * Shows how to follow the improvements process and even participate in the process yourself * Explains how to use new features even before they're widely supported With its comprehensive coverage and friendly, accessible style, JavaScript: The New Toys provides an invaluable resource for programmers everywhere, whether they work in web development, Node.js, Electron, Windows Universal Apps, or another JavaScript environment.
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Seitenzahl: 926
Veröffentlichungsjahr: 2020
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Table of Contents
COVER
INTRODUCTION
WHAT DOES THIS BOOK COVER?
WHO SHOULD READ THIS BOOK
HOW TO USE THIS BOOK
HOW TO CONTACT THE AUTHOR
1 The New Toys in ES2015–ES2020, and Beyond
DEFINITIONS, WHO'S WHO, AND TERMINOLOGY
WHAT ARE THE “NEW TOYS”?
HOW DO NEW TOYS GET CREATED?
KEEPING UP WITH THE NEW TOYS
USING TODAY'S TOYS IN YESTERDAY'S ENVIRONMENTS, AND TOMORROW'S TOYS TODAY
REVIEW
NOTES
2 Block-Scoped Declarations: let and const
AN INTRODUCTION TO LET AND CONST
TRUE BLOCK SCOPE
REPEATED DECLARATIONS ARE AN ERROR
HOISTING AND THE TEMPORAL DEAD ZONE
A NEW KIND OF GLOBAL
CONST: CONSTANTS FOR JAVASCRIPT
BLOCK SCOPE IN LOOPS
OLD HABITS TO NEW
NOTE
3 New Function Features
ARROW FUNCTIONS AND LEXICAL THIS, SUPER, ETC.
DEFAULT PARAMETER VALUES
“REST” PARAMETERS
TRAILING COMMAS IN PARAMETER LISTS AND FUNCTION CALLS
THE FUNCTION NAME PROPERTY
FUNCTION DECLARATIONS IN BLOCKS
OLD HABITS TO NEW
4 Classes
WHAT IS A CLASS?
INTRODUCING THE NEW CLASS SYNTAX
COMPARING WITH THE OLDER SYNTAX
CREATING SUBCLASSES
LEAVING OFF OBJECT.PROTOTYPE
NEW.TARGET
CLASS DECLARATIONS VS. CLASS EXPRESSIONS
MORE TO COME
OLD HABITS TO NEW
NOTES
5 New Object Features
COMPUTED PROPERTY NAMES
SHORTHAND PROPERTIES
GETTING AND SETTING AN OBJECT'S PROTOTYPE
METHOD SYNTAX, AND SUPER OUTSIDE CLASSES
SYMBOL
NEW OBJECT FUNCTIONS
SYMBOL.TOPRIMITIVE
PROPERTY ORDER
PROPERTY SPREAD SYNTAX
OLD HABITS TO NEW
NOTES
6 Iterables, Iterators, for-of, Iterable Spread, Generators
ITERATORS, ITERABLES, THE FOR-OF LOOP, AND ITERABLE SPREAD SYNTAX
GENERATOR FUNCTIONS
OLD HABITS TO NEW
NOTES
7 Destructuring
OVERVIEW
BASIC OBJECT DESTRUCTURING
BASIC ARRAY (AND ITERABLE) DESTRUCTURING
DEFAULTS
REST SYNTAX IN DESTRUCTURING PATTERNS
USING DIFFERENT NAMES
COMPUTED PROPERTY NAMES
NESTED DESTRUCTURING
PARAMETER DESTRUCTURING
DESTRUCTURING IN LOOPS
OLD HABITS TO NEW
NOTES
8 Promises
WHY PROMISES?
PROMISE FUNDAMENTALS
USING AN EXISTING PROMISE
ADDING HANDLERS TO ALREADY SETTLED PROMISES
CREATING PROMISES
OTHER PROMISE UTILITY METHODS
PROMISE PATTERNS
PROMISE ANTI-PATTERNS
PROMISE SUBCLASSES
OLD HABITS TO NEW
NOTES
9 Asynchronous Functions, Iterators, and Generators
ASYNC FUNCTIONS
ASYNC ITERATORS, ITERABLES, AND GENERATORS
OLD HABITS TO NEW
NOTES
10 Templates, Tag Functions, and New String Features
TEMPLATE LITERALS
IMPROVED UNICODE SUPPORT
ITERATION
NEW STRING METHODS
UPDATES TO THE MATCH, SPLIT, SEARCH, AND REPLACE METHODS
OLD HABITS TO NEW
NOTES
11 New Array Features, Typed Arrays
NEW ARRAY METHODS
ITERATION, SPREAD, DESTRUCTURING
STABLE ARRAY SORT
TYPED ARRAYS
OLD HABITS TO NEW
NOTES
12 Maps and Sets
MAPS
SETS
WEAKMAPS
WEAKSETS
OLD HABITS TO NEW
NOTES
13 Modules
INTRODUCTION TO MODULES
MODULE FUNDAMENTALS
RENAMING EXPORTS
RE-EXPORTING EXPORTS FROM ANOTHER MODULE
RENAMING IMPORTS
IMPORTING A MODULE'S NAMESPACE OBJECT
EXPORTING ANOTHER MODULE'S NAMESPACE OBJECT
IMPORTING A MODULE JUST FOR SIDE EFFECTS
IMPORT AND EXPORT ENTRIES
IMPORTS ARE LIVE AND READ-ONLY
MODULE INSTANCES ARE REALM-SPECIFIC
HOW MODULES ARE LOADED
IMPORT/EXPORT SYNTAX REVIEW
DYNAMIC IMPORT
TREE SHAKING
BUNDLING
IMPORT METADATA
WORKER MODULES
OLD HABITS TO NEW
14 Reflection—Reflect and Proxy
REFLECT
PROXY
OLD HABITS TO NEW
NOTES
15 Regular Expression Updates
THE FLAGS PROPERTY
NEW FLAGS
NAMED CAPTURE GROUPS
LOOKBEHIND ASSERTIONS
UNICODE FEATURES
OLD HABITS TO NEW
NOTES
16 Shared Memory
INTRODUCTION
HERE THERE BE DRAGONS!
BROWSER SUPPORT
SHARED MEMORY BASICS
MEMORY IS SHARED, NOT OBJECTS
RACE CONDITIONS, OUT-OF-ORDER STORES, STALE VALUES, TEARING, AND MORE
THE ATOMICS OBJECT
SHARED MEMORY EXAMPLE
HERE THERE BE DRAGONS! (AGAIN)
OLD HABITS TO NEW
NOTES
17 Miscellany
BIGINT
NEW INTEGER LITERALS
NEW MATH METHODS
EXPONENTIATION OPERATOR (**)
DATE.PROTOTYPE.TOSTRING CHANGE
FUNCTION.PROTOTYPE.TOSTRING CHANGE
NUMBER ADDITIONS
SYMBOL.ISCONCATSPREADABLE
VARIOUS SYNTAX TWEAKS
VARIOUS STANDARD LIBRARY / GLOBAL ADDITIONS
ANNEX B: BROWSER-ONLY FEATURES
TAIL CALL OPTIMIZATION
OLD HABITS TO NEW
NOTES
18 Upcoming Class Features
PUBLIC AND PRIVATE CLASS FIELDS, METHODS, AND ACCESSORS
OLD HABITS TO NEW
NOTES
19 A Look Ahead …
TOP-LEVEL AWAIT
WEAKREFS AND CLEANUP CALLBACKS
REGEXP MATCH INDICES
STRING.PROTOTYPE.REPLACEALL
ATOMICS ASYNCWAIT
VARIOUS SYNTAX TWEAKS
LEGACY DEPRECATED REGEXP FEATURES
THANK YOU FOR READING!
NOTES
APPENDIX: Fantastic Features and Where to Find ThemFantastic Features and Where to Find Them
FEATURES IN ALPHABETICAL ORDER
NEW FUNDAMENTALS
NEW SYNTAX, KEYWORDS, OPERATORS, LOOPS, AND SIMILAR
NEW LITERAL FORMS
STANDARD LIBRARY ADDITIONS AND CHANGES
MISCELLANEOUS
INDEX
END USER LICENSE AGREEMENT
List of Tables
Chapter 10
TABLE 10-1: Code Points and Code Units Examples
Chapter 11
TABLE 11-1: The Eleven Typed Arrays
Chapter 13
TABLE 13-1: Import Statements and Import Entries
TABLE 13-2
Chapter 14
TABLE 14-1: Other Reflect Functions
TABLE 14-2: Proxy Traps
Chapter 16
TABLE 16-1
Chapter 17
TABLE 17-1: General Math Functions
TABLE 17-2: Low-Level Math Support Functions
List of Illustrations
Chapter 2
FIGURE 2-1
FIGURE 2-2
FIGURE 2-3
FIGURE 2-4
FIGURE 2-5
FIGURE 2-6
FIGURE 2-7
FIGURE 2-8
Chapter 3
FIGURE 3-1
Chapter 4
FIGURE 4-1
FIGURE 4-2
FIGURE 4-3
FIGURE 4-4
Chapter 5
FIGURE 5-1
FIGURE 5-2
Chapter 7
FIGURE 7-1
FIGURE 7-2
FIGURE 7-3
Chapter 8
FIGURE 8-1
FIGURE 8-2
FIGURE 8-3
FIGURE 8-4
FIGURE 8-5
FIGURE 8-6
FIGURE 8-7
FIGURE 8-8
FIGURE 8-9
Chapter 11
FIGURE 11-1
FIGURE 11-2
FIGURE 11-3
Chapter 12
FIGURE 12-1
FIGURE 12-2
FIGURE 12-3
FIGURE 12-4
FIGURE 12-5
FIGURE 12-6
FIGURE 12-7
Chapter 13
FIGURE 13-1
FIGURE 13-2
FIGURE 13-3
FIGURE 13-4
FIGURE 13-5
FIGURE 13-6
FIGURE 13-7
FIGURE 13-8
FIGURE 13-9
FIGURE 13-10
FIGURE 13-11
FIGURE 13-12
Chapter 15
FIGURE 15-1
Chapter 16
FIGURE 16-1
FIGURE 16-2
FIGURE 16-3
FIGURE 16-4
FIGURE 16-5
Chapter 17
FIGURE 17-1
FIGURE 17-2
Chapter 18
FIGURE 18-1
Guide
Cover
Table of Contents
Begin Reading
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JavaScript®
THE NEW TOYS
T.J. Crowder
NOTES
1
Formerly known as the European Computer Manufacturer's Association (ECMA), but now only the E in Ecma is capitalized in the organization's name.
2
http://www.ecma-international.org/memento/TC39.htm
3
https://tc39.es/ecma262/
4
https://www.electronjs.org/
5
https://reactnative.dev/
6
https://nodejs.org/
7
The committee also cares about significant JavaScript code that isn’t directly related to the web, too.
8
https://tc39.es/ecma402/
9
https://ecma-international.org/memento/join.htm
10
https://github.com/tc39/ecma262
11
https://github.com/tc39/proposals
12
https://es.discourse.group/
13
https://tc39.es/process-document/
14
https://tc39.es/agreements/contributor/
15
https://github.com/tc39/test262
16
https://tc39.es/code-of-conduct/
17
The Discourse instance largely replaces the informal discussion es-discuss mailing list. The list still exists, but many TC39 representatives recommend avoiding its use.
18
At least not properly; it has an incomplete version of let and const.
19
https://github.com/es-shims/es5-shim
20
https://github.com/zloirock/core-js
21
https://github.com/es-shims/
22
https://github.com/google/traceur-compiler
23
http://babeljs.io/
24
http://typescriptlang.org/
25
https://facebook.github.io/jsx/
26
https://reactjs.org/
27
https://babeljs.io/docs/en/babel-preset-env#docsNav
28
https://gulpjs.com/
29
https://gruntjs.com/
30
https://webpack.js.org/
31
http://browserify.org/
32
https://rollupjs.org/
