The document outlines various features of ECMAScript 2015 (ES6) including let, const, classes, modules, arrow functions, promises, and generators. It provides code examples demonstrating the syntax and usage of these features, such as destructuring, spreading operators, and default parameter values. Additionally, it references external resources for further learning about ES6 capabilities.

1. "Agora Nervoso"
"Agora Nervoso"

2. Luís Fernando VendrameLuís Fernando Vendrame
lvendrame@gmail.com
@lvendrame

3. O que era bom ficouO que era bom ficou
melhor ainda!melhor ainda!

4. ECMAScript 2015ECMAScript 2015
let, const, class
modules (export, import)
Destructing arrays e objects
Spread operator
promises (nativo)
Arrow functions
Generators + coroutines
Default parameter values
String templates
Property e método shorthand

5. Lembra do Hooking
Let
Const

6. ConstConst
const myConst = "Meu valor";
myConst = "Novo valor"; //Uncaught TypeError: Assignment to constant varia
//But
const myObj = { prop: 'valor' };
myObj.prop = "Novo valor";// Vai de boas

7. LetLet
function main(){
let a = 10;
for(let i = 0; i < a; i++){
let d = a + i;
}
console.log(d);//Uncaught ReferenceError: d is not defin
}

8. ClassClass
class Shape {
constructor (id, x, y) {
this.id = id
this.move(x, y)
}
move (x, y) {
this.x = x
this.y = y
}
}
class Rectangle extends Shape {
constructor (id, x, y, width, height) {
super(id, x, y)
this.width = width
this.height = height
}
}

9. Arrow FunctionsArrow Functions
x => x * 2;
(x, y) => x + y;
odds = evens.map(v => v + 1);
pairs = evens.map(v => ({ even: v, odd: v + 1 }));
nums = evens.map((v, i) => v + i);

10. Destructuring ArrayDestructuring Array
var list = [ 1, 2, 3 ];
var [ a, , b ] = list; //a = 1, b = 3
[ b, a ] = [ a, b ];

11. Destructuring ObjectDestructuring Object
function getASTNode(){
return {
op: "Olá",
omg: "Nem",
rhs: 35,
lhs: 26,
children: []
};
}
var { op, lhs, rhs } = getASTNode();

12. ModulesModules
// lib/math.js
export function sum (x, y) { return x + y }
export var pi = 3.141593
// someApp.js
import * as math from "lib/math"
console.log("2π = " + math.sum(math.pi, math.pi))
// otherApp.js
import { sum, pi } from "lib/math"
console.log("2π = " + sum(pi, pi))

13. Spread OperatorSpread Operator
var params = [ "hello", true, 7 ]
var other = [ 1, 2, ...params ] // [ 1, 2, "hello", true, 7 ]
//Function with Rest Parameter
function f (x, y, ...a) {
return (x + y) * a.length
}
f(1, 2, ...params) === 9
var str = "foo"
var chars = [ ...str ] // [ "f", "o", "o" ]

14. PromisesPromises
Agora existe uma implementação nativa
compatível com Promises A+.
“
Mas ainda prefiro o Bluebird

15. IteratorsIterators
{
next: function(){
return {
value: ???,
done: true|false;
}
}
myObject[Symbol.iterator]
for(let value of myObject);
//Exemplo
function makeIterator(array){
var nextIndex = 0;
return {
next: function(){
return nextIndex < array.length ?
{value: array[nextIndex++], done: false} :
{done: true};
}
}
}

16. GeneratorsGenerators
function *contar(max){
let i = 0;
while(i<max){
yield i;
i++;
}
return i;
}
var contar10 = contar(10);
console.log(contar.next());//{value: 0, done: false}
console.log(contar.next());//{value: 1, done: false}
console.log(contar.next());//{value: 2, done: false}
console.log(contar.next());//{value: 3, done: false}
console.log(contar.next());//{value: 4, done: false}
console.log(contar.next());//{value: 5, done: false}
console.log(contar.next());//{value: 6, done: false}
console.log(contar.next());//{value: 7, done: false}
console.log(contar.next());//{value: 8, done: false}
console.log(contar.next());//{value: 9, done: false}
console.log(contar.next());//{value: 10, done: true}
console.log(contar.next());//{value: undefined, done: tru

17. GeneratorsGenerators
function* foo(x) {
var y = 2 * (yield (x + 1));
var z = yield (y / 3);
return (x + y + z);
}
var it = foo( 5 );
console.log( it.next() ); // { value:6, done:false }
console.log( it.next( 12 ) ); // { value:8, done:false }
console.log( it.next( 13 ) ); // { value:42, done:true }

18. CoroutinesCoroutines
'use strict'
const co = require('co');
const marked = require('marked');
const fs = require('fs-promise');
const handlebars = require('handlebars');
co(function *() {
let md = yield fs.readFile('README.md');
let html = marked(md.toString());
let template = yield fs.readFile('layout.hbs');
let output = handlebars.compile(template.toString())({
title: 'README',
contents: html
});
yield fs.writeFile('index.html', output);
}).catch(function(err) {
console.error(err.stack);
});

19. Default parameter valueDefault parameter value
function f (x, y = 7, z = 42) {
return x + y + z
}
f(1) === 50
//ECMAScript 5
function f (x, y, z) {
y = y || 7;
if (z === undefined){
z = 42;
}
return x + y + z;
};
f(1) === 50;

20. String templateString template
var customer = { name: "Foo" };
var card = { amount: 7, product: "Bar", unitprice: 42 };
var message = `Hello ${customer.name},
want to buy ${card.amount} ${card.product} for
a total of ${card.amount * card.unitprice} bucks?`;

21. Property & method shorthandProperty & method shorthand
var x = 10;
var y = "eita";
var obj = { x, y };// { x: 10, y: "eita" }
let otherObj = {
foo (a, b) {
…
},
bar (x, y) {
…
},
*quux (x, y) {
…
}
};

22. ReferênciasReferências
http://es6-features.org/
https://developer.mozilla.org/bm/docs/Web/JavaScript
https://davidwalsh.name/es6-generators
http://tobyho.com/2015/12/27/promise-based-coroutines-nodejs/
https://x.st/javascript-coroutines/

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