Author: Jonas Mendes from Huge Rio. This presentation covers what have changed from the previous ES5 version of Javascript, and the main new features of ES6 or ES2015.

2. ECMAScript 2015
Huge

3. 1.What have changed
2. New features
Agenda

4. What have
changed.

5. var
IIFE
function(){}
param=param||"default"
‘Hello’+myVar+‘.'
callbackhell
let
{blocks}
()=>
function(param="default")
`Hello${myVar}.`
promises
ES2015.ES5.
What have changed.

6. What have changed.
1. Let.
2. Blocks.
3. Arrow functions.
4. Default params.
5. String interpolation.
6. Promises.

7. Let.
Whathavechanged.

8. Name.
Let.

9. In computer science,a“let” expression
associates a function definition with a
restricted scope.

10. The“let” expression may also be
defined in mathematics,where it
associates a Boolean condition with a
restricted scope.

11. Scope.
Let.

12. The“let” statement declares a block
scope local variable.
“Let” allows you to declare variables that are limited in scope
to the block, statement, or expression on which it is used.
“Var” variables are limited in scope to the function statement.

13. Use ”let” to define variables
limited in scope to the block.

14. “Var” isn’t dead.
"Let" will make the javascript engine create a new scope for
each block that has a "let" variable in it.

15. Examples.
Let.

21. Temporal dead zone.
Let.

24. Live code
example.

25. Blocks.
Whathavechanged.

26. History.
Blocks.

27. Ideas of block structure were developed
in the 1950s during the development of
the first autocodes,and were formalized
in the Algol 58 and Algol 60 reports.

28. In computer programming,a block or
code block is a section of code which is
grouped together.Blocks consist of one
or more declarations and statements.

29. Blocks narrow the lexical scope of
variables,procedures and functions
declared in it,so that they do not conflict
with variables having the same name
used elsewhere.

30. Other languages.
Blocks.

31. Algol

32. Python

33. Examples.
Blocks.

36. Arrow functions.
Whathavechanged.

37. About.
Arrowfunctions.

38. Arrow functions are always anonymous.
An arrow function expression has a shorter syntax compared to
function expressions and lexically binds the "this" value.

39. Examples.
Arrowfunctions.

41. Lexical "this".

43. Shorter functions.

45. Default params.
Whathavechanged.

47. String interpolation.
Whathavechanged.

52. Promises.
Whathavechanged.

53. About.
Promises.

54. The Promise object is used for deferred
and asynchronous computations.

55. A Promise represents an operation that
hasn't completed yet, but is expected
in the future.

56. The cure.

58. Example.
Promises.

59. Promise chain.
Gates of hell.

60. New

61. Const.
New.

62. In computer programming,a constant is
an identifier with an associated value
which cannot be altered.

63. The const declaration creates
a read-only reference to a value.

65. It does not mean the value
it holds is immutable.

68. Constants are block-scoped.

70. A constant cannot share its name
with a function or a variable
in the same scope.

72. Useful methods.
New.

73. Array Find.
Usefulmethods.

74. The“find” method returns
a single value in the array.

76. And the“filter” method?
What is the difference?

79. Object Assign.
Usefulmethods.

80. The "assign" method is used to copy all
enumerable own properties from one or
more source objects to a target object.

81. Cloning an object.

83. Merging objects.

85. Does he copy the methods too?

87. Spread / Rest.
New.

90. Symbol.
New.

91. A symbol is a unique
and immutable data type.

93. Symbols are the same even
when in other threads.

95. Symbol properties.

97. Iterator & Iterable.
New.

98. The iterator protocol defines a
standard way to produce
a sequence of values.

99. The Iterable protocol allows JavaScript
objects to define or customize their
iteration behavior.

101. This is an iterator.
This is an iterable.

103. Can I create a custom iterator?

108. Generator.
New.

109. Generators are functions which can be
exited and later re-entered.

110. The “function*” declaration defines a
generator function.

111. A generator returns an iterator.

113. Run .. Stop .. Run

116. Questions?