This document provides an overview of new features introduced in ES2015 including block scope, constants, arrow functions, classes, inheritance, and extended built-ins. It discusses browser support for these features and options for using transpilers to enable support in older browsers like Internet Explorer. It also briefly mentions potential future features like enums, pattern matching, and optional type annotations.

1. beyond
and
ES2015

2. ES.next ?
harmony ?
ES6 ?
ES2015 ?

3. ES2015July 2011 - June 2015

4. New features
• classes
• arrows
• enhanced object literals
• template strings
• destructuring
• default + rest + spread
• let + const
• iterators + for..of
• generators
• unicode
• modules
• module loaders
• map + set + weakmap + weakset
• proxies
• symbols
• subclassable built-ins
• promises
• math + number + string + array + object APIs
• binary and octal literals
• reflect api
• tail calls

5. Jay Phelps
Senior Front end engineer | Netflix
Twitter: @_jayphelps

6. Block ScopeInstead of Function Scope

7. Before

8. after

10. constants

13. Chrome41
Browser Support
EDGE12
Safari nope
Firefox 44

14. Destructuring

15. Before

16. after

17. Swapping variables

18. Destructuring parameters

19. Destructuring parameters

20. Chrome45
Browser Support
EDGE13
Safari nope
Firefox 22

21. Arrow Functions

22. Before

23. after

25. lexical `this`

26. lexical `this`
references parent scope `this`

27. lexical `arguments`
references parent scope `arguments`

28. Chrome45
Browser Support
EDGE13
Safari nope
Firefox 22

29. classes

30. Before

31. after

32. syntactic sugar
still uses Prototype-based inheritance

33. Must use `new`

34. Must use `new`

35. classes are not hoisted
Unlike function declarations

36. classes are not hoisted
Unlike function declarations

37. classes are not hoisted
Unlike function declarations

38. class expressions
Similar to Function Expressions

39. Must call `super`before accessing `this`
When you extend, your constructor

40. Inheritance

41. Inheritance

42. Inheritance

43. Inheritance

44. extend built-ins

45. only works with native es2015 support
extending build-ins
not with transpilers alone

46. Chromecoming soon in 49
Browser Support
EDGE13 behind a flag
Safari basic support in 7.1, full support 9
Firefox basic support in 2 (yes, two!), full support 34

47. How can I play today?i.e. I have to support Internet Explorer

48. Use a transpiler

51. Lets gossip

52. rumored features… es2017++ ?!

53. Disclaimer:

54. EnumsAxel Rauschmayer

56. https://gist.github.com/rauschma/
f3e77132319e09b94722

57. Pattern Matching !!!Yehuda katz

58. pattern matching !!!

59. https://github.com/natefaubion/sparkler
Similar syntax of

60. Optional type annotationslike Flow or TypeScript
Macroslike sweet.js
Bonus guesses

61. your voice mattersi.e. bug the tc39 members

62. Twitter: @_jayphelps
That’s all folks