Exploring ES6

What you need to know about this book

1. Audience: JavaScript programmers
2. Why should I read this book?
3. How to read this book
4. Sources of this book
5. Glossary
6. Conventions
7. Demo code on GitHub
8. Sidebars
9. Tips for reading
10. Code on GitHub
11. Information
12. Question
13. Warning
14. External material
15. Related parts of the spec
16. Footnotes

Foreword

Preface

Acknowledgements

About the author

1. IBackground

1.About ECMAScript 6 (ES6)

1. 1.1TC39 (Ecma Technical Committee 39)
2. 1.2How ECMAScript 6 was designed
3. 1.3JavaScript versus ECMAScript
4. 1.4Upgrading to ES6
5. 1.5Goals for ES6
6. 1.6Categories of ES6 features
7. 1.7A brief history of ECMAScript
8. Sources of this section:

2.FAQ: ECMAScript 6

1. 2.1How can I use ES6 today?
2. 2.2Isn’t ECMAScript 6 now called ECMAScript 2015?
3. 2.3How do I migrate my ECMAScript 5 code to ECMAScript 6?
4. 2.4Does it still make sense to learn ECMAScript 5?
5. 2.5Is ES6 bloated?
6. 2.6Isn’t the ES6 specification very big?
7. 2.7Does ES6 have array comprehensions?
8. 2.8Is ES6 statically typed?

3.One JavaScript: avoiding versioning in ECMAScript 6

1. 3.1Versioning
2. 3.2Strict mode and ECMAScript 6
3. 3.3Breaking changes in ES6
4. 3.4Conclusion
5. 3.5Further reading

4.Core ES6 features

1. 4.1From var to const/let
2. 4.2From IIFEs to blocks
3. 4.3From concatenating strings to template literals
4. 4.4From function expressions to arrow functions
5. 4.5Handling multiple return values
6. 4.6From for to forEach() to for-of
7. 4.7Handling parameter default values
8. 4.8Handling named parameters
9. 4.9From arguments to rest parameters
10. 4.10From apply() to the spread operator (...)
11. 4.11From concat() to the spread operator (...)
12. 4.12From function expressions in object literals to method definitions
13. 4.13From constructors to classes
14. 4.14From custom error constructors to subclasses of Error
15. 4.15From objects to Maps
16. 4.16New string methods
17. 4.17New Array methods
18. 4.18From CommonJS modules to ES6 modules
19. 4.19What to do next
20. IIData

5.New number and Math features

1. 5.1Overview
2. 5.2New integer literals
3. 5.3New static Number properties
4. Source of this section
5. 5.4New Math functionality
6. 5.5FAQ: numbers

6.New string features

1. 6.1Overview
2. 6.2Unicode code point escapes
3. 6.3String interpolation, multi-line string literals and raw string literals
4. 6.4Iterating over strings
5. Remaining problem: combining marks
6. 6.5Numeric values of code points
7. 6.6Checking for inclusion
8. 6.7Repeating strings
9. 6.8String methods that delegate regular expression work to their parameters
10. 6.9Reference: the new string methods

7.Symbols

1. 7.1Overview
2. 7.2A new primitive type
3. 7.3Using symbols to represent concepts
4. 7.4Symbols as keys of properties
5. 7.5Converting symbols to other primitive types
6. 7.6Wrapper objects for symbols
7. 7.7Crossing realms with symbols
8. 7.8FAQ: symbols
9. 7.9The spelling of well-known symbols: why Symbol.iterator and not Symbol.ITERATOR (etc.)?
10. 7.10The symbol API

8.Template literals

1. 8.1Overview
2. 8.2Introduction
3. Spec: line terminators in template literals
4. 8.3Examples of using tagged template literals
5. 8.4Implementing tag functions
6. Tagged template literals in the spec
7. Escaping in tagged template literals in the spec
8. 8.5FAQ: template literals and tagged template literals

9.Variables and scoping

1. 9.1Overview
2. 9.2Block scoping via let and const
3. 9.3const creates immutable variables
4. Spec detail: changing a const variable always throws a TypeError
5. 9.4The temporal dead zone
6. 9.5let and const in loop heads
7. for loop: per-iteration bindings in the spec
8. for-of loop: per-iteration bindings in the spec
9. 9.6Parameters as variables
10. 9.7The global object
11. 9.8Function declarations and class declarations
12. 9.9Coding style: const versus let versus var

10.Destructuring

1. 10.1Overview
2. 10.2Background: Constructing data versus extracting data
3. 10.3Patterns for destructuring
4. 10.4How do patterns access the innards of values?
5. 10.5Default values
6. Still confused?
7. 10.6More object destructuring features
8. 10.7More Array destructuring features
9. 10.8You can assign to more than just variables
10. 10.9Pitfalls of destructuring
11. 10.10Examples of destructuring
12. 10.11The destructuring algorithm

11.Parameter handling

1. 11.1Overview
2. 11.2Parameter handling as destructuring
3. 11.3Parameter default values
4. 11.4Rest parameters
5. 11.5Simulating named parameters
6. 11.6Examples of destructuring in parameter handling
7. 11.7Coding style tips
8. 11.8The spread operator (...)
9. IIIModularity

12.Callable entities in ECMAScript 6

1. 12.1Overview
2. 12.2Ways of calling in ES6
3. 12.3Recommendations for using callable entities
4. 12.4ES6 callable entities in detail
5. 12.5Dispatched and direct method calls in ES5 and ES6
6. 12.6The name property of functions
7. 12.7FAQ: callable entities

13.Arrow functions

1. 13.1Overview
2. 13.2Traditional functions are bad non-method functions, due to this
3. 13.3Arrow function syntax
4. 13.4Lexical variables
5. 13.5Syntax pitfalls
6. 13.6Immediately-invoked arrow functions
7. 13.7Arrow functions versus bind()
8. 13.8Arrow functions versus normal functions
9. 13.9FAQ: arrow functions

14.New OOP features besides classes

1. 14.1Overview
2. 14.2New features of object literals
3. 14.3New methods of Object
4. 14.4Traversing properties in ES6
5. 14.5Assigning versus defining properties
6. 14.6__proto__ in ECMAScript 6
7. 14.7Enumerability in ECMAScript 6
8. 14.8Customizing basic language operations via well-known symbols
9. 14.9FAQ: object literals

15.Classes

1. 15.1Overview
2. 15.2The essentials
3. 15.3Private data for classes
4. 15.4Simple mixins
5. 15.5The details of classes
6. 15.6The details of subclassing
7. Methods are a special kind of function now
8. 15.7The species pattern
9. 15.8The pros and cons of classes
10. traits.js: traits library for JavaScript
11. 15.9FAQ: classes
12. 15.10What is next for classes?
13. 15.11Further reading

16.Modules

1. 16.1Overview
2. 16.2Modules in JavaScript
3. 16.3The basics of ES6 modules
4. 16.4Importing and exporting in detail
5. 16.5The ECMAScript 6 module loader API
6. The module loader API is not part of the ES6 standard
7. The module loader API is work in progress
8. 16.6Using ES6 modules in browsers
9. Support for ES6 modules in browsers is work in progress
10. Sources of this section
11. 16.7Details: imports as views on exports
12. 16.8Design goals for ES6 modules
13. 16.9FAQ: modules
14. 16.10Advantages of ECMAScript 6 modules
15. 16.11Further reading
16. IVCollections

17.The for-of loop

1. 17.1Overview
2. 17.2Introducing the for-of loop
3. 17.3Pitfall: for-of only works with iterable values
4. 17.4Iteration variables: const declarations versus var declarations
5. 17.5Iterating with existing variables, object properties and Array elements
6. 17.6Iterating with a destructuring pattern

18.New Array features

1. 18.1Overview
2. 18.2New static Array methods
3. 18.3New Array.prototype methods
4. 18.4ES6 and holes in Arrays
5. 18.5Configuring which objects are spread by concat() (Symbol.isConcatSpreadable)
6. Symbol.isConcatSpreadable in the ES6 spec
7. 18.6The numeric range of Array indices
8. Enforcing the smaller range of normal Arrays

19.Maps and Sets

1. 19.1Overview
2. 19.2Map
3. 19.3WeakMap
4. 19.4Set
5. 19.5WeakSet
6. 19.6FAQ: Maps and Sets

20.Typed Arrays

1. 20.1Overview
2. 20.2Introduction
3. 20.3ArrayBuffers
4. 20.4Typed Arrays
5. 20.5DataViews
6. 20.6Browser APIs that support Typed Arrays
7. 20.7Extended example: JPEG SOF0 decoder
8. 20.8Availability

21.Iterables and iterators

1. 21.1Overview
2. 21.2Iterability
3. 21.3Iterable data sources
4. 21.4Iterating language constructs
5. 21.5Implementing iterables
6. 21.6More examples of iterables
7. 21.7FAQ: iterables and iterators
8. 21.8The ECMAScript 6 iteration protocol in depth

22.Generators

1. 22.1Overview
2. 22.2What are generators?
3. 22.3Generators as iterators (data production)
4. 22.4Generators as observers (data consumption)
5. Further reading
6. 22.5Generators as coroutines (cooperative multitasking)
7. 22.6Examples of generators
8. 22.7Inheritance within the iteration API (including generators)
9. 22.8Style consideration: whitespace before and after the asterisk
10. 22.9FAQ: generators
11. 22.10Conclusion
12. 22.11Further reading
13. VStandard library

23.New regular expression features

1. 23.1Overview
2. 23.2New flag /y (sticky)
3. 23.3New flag /u (unicode)
4. 23.4New data property flags
5. 23.5RegExp() can be used as a copy constructor
6. 23.6String methods that delegate to regular expression methods
7. Further reading

24.Asynchronous programming (background)

1. 24.1The JavaScript call stack
2. 24.2The browser event loop
3. 24.3Receiving results asynchronously
4. 24.4Looking ahead
5. 24.5Further reading

25.Promises for asynchronous programming

1. 25.1Overview
2. 25.2Introduction: Promises
3. 25.3A first example
4. 25.4Three ways of understanding Promises
5. 25.5Creating and using Promises
6. 25.6Examples
7. 25.7Other ways of creating Promises
8. 25.8Chaining Promises
9. 25.9Common Promise chaining mistakes
10. 25.10Tips for error handling
11. 25.11Composing Promises
12. 25.12Two useful additional Promise methods
13. 25.13Node.js: using callback-based sync functions with Promises
14. 25.14ES6-compatible Promise libraries
15. 25.15Next step: using Promises via generators
16. 25.16Promises in depth: a simple implementation
17. 25.17Advantages and limitations of Promises
18. 25.18Reference: the ECMAScript 6 Promise API
19. 25.19Further reading
20. VIMiscellaneous

26.Unicode in ES6

1. 26.1Unicode is better supported in ES6
2. 26.2Escape sequences in ES6
3. Further reading

27.Tail call optimization

1. 27.1What is tail call optimization?
2. 27.2Checking whether a function call is in a tail position
3. 27.3Tail-recursive functions

28.Metaprogramming with proxies

1. 28.1Overview
2. 28.2Programming versus metaprogramming
3. 28.3Proxies explained
4. 28.4Use cases for proxies
5. 28.5The design of the proxy API
6. 28.6FAQ: proxies
7. 28.7Reference: the proxy API
8. 28.8Conclusion
9. 28.9Further reading

29.Coding style tips for ECMAScript 6

30.An overview of what’s new in ES6

1. 30.1Categories of ES6 features
2. 30.2New number and Math features
3. 30.3New string features
4. 30.4Symbols
5. 30.5Template literals
6. 30.6Variables and scoping
7. 30.7Destructuring
8. 30.8Parameter handling
9. 30.9Callable entities in ECMAScript 6
10. 30.10Arrow functions
11. 30.11New OOP features besides classes
12. 30.12Classes
13. 30.13Modules
14. 30.14The for-of loop
15. 30.15New Array features
16. 30.16Maps and Sets
17. 30.17Typed Arrays
18. 30.18Iterables and iterators
19. 30.19Generators
20. 30.20New regular expression features
21. 30.21Promises for asynchronous programming
22. 30.22Metaprogramming with proxies