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<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>ECMAScript 6 => pure awesomness</title>
<meta name="description" content="A framework for easily creating beautiful presentations using HTML">
<meta name="author" content="Hakim El Hattab">
<meta name="apple-mobile-web-app-capable" content="yes" />
<meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
<link rel="stylesheet" href="css/reveal.min.css">
<link rel="stylesheet" href="css/theme/default.css" id="theme">
<link rel="stylesheet" href="css/custom.css">
<!-- For syntax highlighting -->
<link rel="stylesheet" href="lib/css/zenburn.css">
<!-- If the query includes 'print-pdf', include the PDF print sheet -->
<script>
if( window.location.search.match( /print-pdf/gi ) ) {
var link = document.createElement( 'link' );
link.rel = 'stylesheet';
link.type = 'text/css';
link.href = 'css/print/pdf.css';
document.getElementsByTagName( 'head' )[0].appendChild( link );
}
</script>
<!--[if lt IE 9]>
<script src="lib/js/html5shiv.js"></script>
<![endif]-->
</head>
<body>
<div class="reveal">
<!-- Any section element inside of this container is displayed as a slide -->
<div class="slides">
<section>
<h1>ECMAScript 6 => `${pure}<br>awesomness`</h1>
</section>
<section>
<h2>About me:</h2>
<ul>
<li>Marcin Kumorek</li>
<li>Front-end developer @platformui</li>
<li><a href="http://twitter.com/qmmr" target="_blank">@qmmr</a></li>
<li><a href="http://plus.google.com/+MarcinKumorekProfile" target="_blank">Google+</a></li>
<li><a href="https://github.com/qmmr">github.com/qmmr</a></li>
</ul>
</section>
<section>
<section>
<h1>A brief history of JavaScript</h1>
<ul>
<li class="fragment">created in 10 days in May 1995 by Brendan Eich, an engineer at Netscape</li>
<li class="fragment">first released with Netscape 2 early in 1996</li>
<li class="fragment">originally called Mocha, renamed to LiveScript to reflect its dynamic nature</li>
<li class="fragment">finally renamed to JavaScript after the popular Sun Microsystem's Java language</li>
</ul>
</section>
<section>
<h2><span style="text-decoration: line-through;">Mocha</span> JavaScript flavors</h2>
<ul>
<li class="fragment">Microsoft released a mostly-compatible version of the language called JScript with IE 3 several months later</li>
<li class="fragment">ECMAScript standard in 1997</li>
<li class="fragment">The standard received a significant update as ECMAScript edition 3 in 1999</li>
<li class="fragment">The fourth edition was abandoned.</li>
<li class="fragment">ECMAScript edition 5, published in December of 2009</li>
<li class="fragment">ECMAScript 6 (ES6 Harmony) - work in progress</li>
</ul>
<aside class="notes">
- LiveScript was renamed to JavaScript (because of popularity of Java) edespite the two having very little in common. This has been a source of confusion ever since.
- Netscape submitted the language to European Computer Manufacturers Association which resulted in the first edition of the ECMAScript standard in 1997.
- ECMAScript edition 3 in 1999 and has stayed pretty much stable ever since
- The fourth edition was abandoned, due to political differences concerning language complexity.
- Many parts of the fourth edition formed a basis of the new ECMAScript edition 5, published in December of 2009
</aside>
</section>
</section>
<section>
<section>
<h1>ES6 finally</h1>
</section>
<section>
<h2>Let's dive in!</h2>
</section>
<section>
<img src="img/almost-there.jpg" alt="ES6 - almost there...">
<p>Almost there...</p>
</section>
<section>
<p>Available resources:</p>
<ul>
<li><a href="http://kangax.github.io/es5-compat-table/es6/">kangax.github.io/es5-compat-table/es6</a></li>
<li><a href="http://www.es6fiddle.net/">www.es6fiddle.net</a></li>
<li><a href="https://github.com/nzakas/understandinges6/blob/master/manuscript/01-The-Basics.md">understanding es6</a></li>
<li><a href="https://github.com/lukehoban/es6features">github.com/lukehoban/es6features</a></li>
<li><a href="https://twitter.com/esdiscuss">@esdiscuss</a></li>
</ul>
</section>
</section>
<section>
<section>
<h1>What's coming?</h1>
</section>
<section>
<h2>Syntax refinements:</h2>
<ul>
<li class="fragment"><a href="#/5/1">=> (arrow)</a></li>
<li class="fragment"><a href="#/5/6">object literals</a></li>
</ul>
</section>
<section>
<h2>New syntax:</h2>
<ul>
<li class="fragment"><a href="#/6/1">let</a></li>
<li class="fragment"><a href="#/6/6">const</a></li>
<li class="fragment"><a href="#/6/10">default parameters</a></li>
<li class="fragment"><a href="#/6/13">rest</a></li>
<li class="fragment"><a href="#/6/16">spread</a></li>
<li class="fragment"><a href="#/6/22">destructuring</a></li>
<li class="fragment"><a href="#/6/29">for..of loop</a></li>
<li class="fragment"><a href="#/6/32">iterators</a></li>
<li class="fragment"><a href="#/6/34">generators</a></li>
<li class="fragment"><a href="#/6/41">comprehensions</a></li>
</ul>
</section>
<section>
<h2>Organizational features:</h2>
<ul>
<li class="fragment">classes</li>
<li class="fragment">modules</li>
</ul>
</section>
<section>
<h2>New standard library features:</h2>
<ul>
<li class="fragment">set</li>
<li class="fragment">map</li>
<li class="fragment">weakmap + weakset</li>
<li class="fragment">promises</li>
<li class="fragment">proxies</li>
</ul>
</section>
<section>
<h2>...rest</h2>
<ul>
<li class="fragment">template strings</li>
// template literals
`string text`
// Multiline strings
`string text line 1
string text line 2`
// String interpolation
`string text ${expression} string text`
var greet = function(greet = 'Hello', name = 'stranger') {
return `${ greet } ${ name },
how are you today?`;
};
console.log(greet());
"Hello stranger,
how are you today?"
console.log(greet('Hi', 'Marcin'));
"Hi Marcin,
how are you today?"
---
var lovem = function(strings, ...vars) {
return `${ vars[0] } <3 ${ strings[1] }!`;
};
var user = 'Marcin';
// syntax - tagged template
console.log(lovem `${ user }ECMAScript2015`);
<li class="fragment">unicode</li>
<li class="fragment">module loaders</li>
<li class="fragment">symbols</li>
<li class="fragment">subclassable built-ins</li>
<li class="fragment">math + number + string + object APIs</li>
<li class="fragment">binary and octal literals</li>
<li class="fragment">reflect api</li>
<li class="fragment">tail calls</li>
</ul>
</section>
</section>
<!-- PART ONE -->
<section>
<section>
<h1>Part one</h1>
</section>
<!-- SYNTAX REFINEMENTS -->
<section>
<h1>Syntax refinements</h1>
</section>
<!-- ### => (arrow) ### -->
<section>
<h1>=> (arrow)</h1>
<ul>
<li>shorter syntax for common case use of anonymous functions</li>
<li>retains lexical scope of <strong>this</strong></p></li>
</ul>
</section>
<section>
<h2>shorter syntax for common case use of anonymous functions</h2>
<p>old way</p>
<pre><code data-trim contenteditable>
var reflect = function(value) {
return value;
};
var reflect = value => value;
or
var reflect = (value) => {
return value;
}
---
var sum = function(a, b) {
return a + b;
};
var sum = (a, b) => a + b;
// OR
var sum = (a, b) => {
return a + b;
};
---
var getName = function() {
return 'Marcin';
};
var getName = () => 'Marcin';
---
var square = function(n) {
return n * n;
};
var numbers = [ 0, 1, 2, 3, 4, 5 ];
var doubles = numbers.map( square ); // [ 0, 1, 4, 9, 16, 25 ]
var numbers = [ 0, 1, 2, 3, 4, 5 ];
var doubles = numbers.map( n => n * n ); // [ 0, 1, 4, 9, 16, 25 ]
</code></pre>
</section>
<section>
<p>new way</p>
<pre><code data-trim contenteditable>
let people = [
{
name: 'Joe',
lastName: 'Doe',
occupation: 'Web Developer',
languages: [ 'HTML', 'CSS', 'JavaScript' ]
},
{
name: 'Jane',
lastName: 'Doe',
occupation: 'Back-end Developer',
languages: [ 'PHP', 'Ruby', 'Python', 'JavaScript' ]
}
]
</code></pre>
</section>
<section>
<h2>retains lexical scope of <strong>this</strong></p></h2>
<p>old way</p>
<pre><code data-trim contenteditable>
var person = {
name: 'Joe',
friends: [ 'Jane', 'Johnny', 'Luke' ],
getName: function() {
setTimeout(function() {
console.log(this.name);
}, 1000);
},
showFriends: function() {
return this.friends.map(function(friend) {
return `${ this.name } is friend with ${ friend }`;
});
}
};
var person = {
name: 'Joe',
friends: [ 'Jane', 'Johnny', 'Luke' ],
getName: function() {
var that = this;
setTimeout(function() {
console.log(that.name);
}, 1000);
},
showFriends: function() {
var self = this;
return this.friends.map(function(friend) {
return `${ self.name } is friend with ${ friend }`;
});
}
};
var person = {
name: 'Joe',
friends: [ 'Jane', 'Johnny', 'Luke' ],
getName: function() {
setTimeout(function() {
console.log(this.name);
}.bind(this), 1000);
},
showFriends: function() {
return this.friends.map(function(friend) {
return `${ this.name } is friend with ${ friend }`;
}, this);
}
};
var person = {
name: 'Joe',
friends: [ 'Jane', 'Johnny', 'Luke' ],
getName() {
setTimeout(() => console.log(this.name), 1000);
},
showFriends() {
return this.friends.map(friend => `${ this.name } is friend with ${ friend }`)
}
};
console.log(person.getName())
console.log(person.showFriends())
</code></pre>
</section>
<section>
<h2>new way</h2>
<pre><code data-trim contenteditable>
let person = {
name: 'Joe',
friends: [ 'Jane', 'Johnny', 'Luke' ],
getName() {
setTimeout(() => console.log( 'Hi, my name is ' + this.name ), 1000);
},
showFriends() {
this.friends.forEach( friend => console.log( this.name + ' is friend with ' + friend ) );
}
};
person.getName();
person.showFriends();
</code></pre>
<aside class="notes">
es6fiddle
</aside>
</section>
<!-- ### refined object literals ### -->
<section>
<h1>Refined object literals</h1>
</section>
<section>
<h2>object literals</h2>
<p>old way</p>
<pre><code data-trim contenteditable>
var teacher = 'Michael'
var student = {
name: 'Joe',
teacher: teacher,
greet: function () {
return 'Hi, ' + this.name + '!'
}
}
student[ '_id_' + +new Date() ] = Math.floor( Math.random() * 10000000 )
</code></pre>
</section>
<section>
<h2>object literals</h2>
<p>new way</p>
<pre>
<code data-trim contenteditable>
// ES5
var title = 'ECMAScript 2015';
var students = [ 'Joe', 'Jane', 'Phil' ];
var id = function() { return 42 };
var course = {
title: title,
students: students,
welcome: function() {
return 'Welcome to ' + this.title + ' course!';
}
};
course[ '_prop_' + id() ] = id();
// ES6
var title = 'ECMAScript 2015';
var students = [ 'Joe', 'Jane', 'Phil' ];
var id = function() { return 42 };
var course = {
title,
students,
welcome() {
return `Welcome to ${ this.title } course!`;
},
[ `_prop_${ id() }` ]: id() // ['_prop42']: 42
};
for (let key of Object.keys(course)) {
console.log(`Course.${ key } = ${ course[key] }`)
}
</code>
</pre>
</section>
<!-- ### new syntax ### -->
<section>
<h1>New syntax</h1>
</section>
<!-- ### let keyword ### -->
<section>
<h1>let</h1>
<h2>is the new var</h3>
<p class="fragment">scoped to the block rather then function</p>
<p class="fragment">does not have hoisting characteristics</p>
<aside class="notes">
block being anything inside curly braces
- loops
- if/else/else if
- switch
- try/catch*
</aside>
</section>
<section>
<h2>scoped inside if clause</h2>
<pre><code data-trim contenteditable>
function printName ( language ) {
var name = 'Marcin';
if ( language === 'English' ) {
let name = 'Martin';
console.log( name ); // Martin
}
console.log( name ); // Marcin
}
---
function func() {
let foo = 5;
if (1) {
let foo = 10; // shadows outer `foo`
console.log(foo); // 10
}
console.log(foo); // 5
}
---
if (true) { // enter new scope, TDZ starts
// Uninitialized binding for `tmp` is created
console.log(typeof tmp); // ReferenceError
tmp = 'abc'; // ReferenceError
console.log(tmp); // ReferenceError
let tmp; // TDZ ends, `tmp` is initialized with `undefined`
console.log(tmp); // undefined
tmp = 123;
console.log(tmp); // 123
}
</code></pre>
<aside class="notes">
you cannot redeclare identifier, throws syntax error
</aside>
</section>
<section>
<h2>Local scopes</h2>
<p>common problem</p>
<pre><code data-trim contenteditable>
function wrapper ( arr ) {
var result = [], i, len;
for ( i = 0, len = arr.length; i < len; ++i ) {
result[i] = function () {
return arr[i];
}
}
return result
}
var wrapped = wrapper([ 'Luke', 'Obi-Wan', 'Yoda' ]);
console.log( wrapped[1]() ); // undefined
---
let arr = [];
for (var i=0; i < 3; i++) {
arr.push(function() {
return i;
});
}
arr.map(function(x) {
return x();
}); // [ 3, 3, 3 ]
</code></pre>
<h2 class="look fragment fade-in">ಠ_ಠ</h2>
</section>
<section>
<h2>Old solution</h2>
<pre><code data-trim contenteditable>
function wrapper ( arr ) {
var result = [], i, len;
for ( i = 0, len = arr.length; i < len; ++i ) {
(function ( j ) {
result[i] = function () { return arr[j] }
})( i )
}
return result;
}
var wrapped = wrapper([ 'Luke', 'Obi-Wan', 'Yoda' ]);
console.log( wrapped[2]() ); // 'Yoda'
</code></pre>
<h2 class="look fragment fade-in">ಠಿ_ಠ</h2>
</section>
<section>
<h2>New solution</h2>
<pre><code data-trim contenteditable>
function wrapper ( arr ) {
var result = [];
for ( let i = 0, len = arr.length; i < len; ++i ) {
result[i] = function () { return arr[i] }
}
return result;
}
var wrapped = wrapper([ 'Luke', 'Obi-Wan', 'Yoda' ]);
console.log( wrapped[1]() ); // 'Obi-Wan'
</code></pre>
<h2 class="look fragment fade-in">＼(｀0´)／</h2>
</section><!-- end ### let keyword ### -->
<!-- ### const keyword ### -->
<section>
<h1>const</h1>
<p class="fragment">similar to let, block scoped</p>
<aside class="notes">
- block being anything inside curly braces
- loops
- if/else/else if
- switch
- try/catch*
</aside>
</section>
<section>
<h2>once declared, cannot be redeclared</h2>
<pre><code data-trim contenteditable>
const FOO = 'hello world';
FOO = 'Goodbye, world!'; // error
</code></pre>
</section>
<section>
<h2>declaration must be followed<br> by assignment</h2>
<pre><code data-trim contenteditable>
const FOO;
console.log( FOO ); // undefined
FOO = 'hello world!'; // error: cannot reasign const
</code></pre>
<aside class="notes">
- otherwise we have undefined value, that we cannot change (sic!)
- IE will give an error, others will ignore it (Firefox)
</aside>
</section>
<section>
<h2>const can hold any type of variables (array, object etc.)</h2>
<pre><code data-trim contenteditable>
const FOO = [];
FOO.push( 'Hello' );
FOO.push( 'world!' );
console.log(FOO.join( ', ' )); // Hello, world!
</code></pre>
<pre><code data-trim contenteditable>
const BAR = {};
BAR.baz = 'Hello, world!';
console.log( BAR.baz ); // hello, world!
--
Object.assign()
var alias = 'Spider-man';
var person = {
firstName: 'Peter',
lastName: 'Parker'
};
var superpowers = [ 'web', 'wall-climbing' ];
var peter = Object.assign({}, person, { alias: alias }, { superpowers: superpowers });
console.log(JSON.stringify(peter));
/*
{
"alias": "Spider-man",
"firstName": "Peter",
"lastName": "Parker",
"superpowers": [ "web", "wall-climbing" ]
}
*/
---
var alias = 'Spider-man';
var person = {
firstName: 'Peter',
lastName: 'Parker'
};
var superpowers = [ 'web', 'wall-climbing' ];
var peter = Object.assign({}, person, { alias, superpowers });
console.log(JSON.stringify(peter));
/*
{
"alias": "Spider-man",
"firstName": "Peter",
"lastName": "Parker",
"superpowers": [ "web", "wall-climbing" ]
}
*/
</code></pre>
</section><!-- end ### const ### -->
<!-- ### default parameters ### -->
<section>
<h1>default parameters</h1>
<h2 class="look fragment">ʘ‿ʘ</h2>
</section>
<section>
<h2>checking for optional params</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
function createCustomElement (tagName, id, parent) {
if (!id) {
id = generateID();
}
if (!parent) {
parent = document.body;
}
var element = document.createElement( tagName );
element.id = id;
parent.appendChild(element);
return element;
}
function makeRequest(url, timeout, callback) {
timeout = timeout || 2000;
callback = callback || function() {};
// the rest of the function
}
function makeRequest(url, timeout = 2000, callback = function() {}) {
// the rest of the function
}
---
function timeout(timeout = 2000, callback = function() {}) {
// the rest of the function
}
---
function getCallback() {
return function() {};
}
function timeout(timeout = 2000, getCallback()) {
// the rest of the function
}
---
// uses default timeout and callback
makeRequest('/foo');
// uses default callback
makeRequest('/foo', 500);
// doesn't use defaults
makeRequest('/foo', 500, function(el) {
doSomething(el);
});
var getCallback = function() {
return function callback() {}
};
function makeRequest(url, timeout = 2000, callback = getCallback()) {
// the rest of the function
}
</code></pre>
</section>
<section>
<h2>assignment inside parenthesis</h2>
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
function createCustomElement (tagName = 'div', id = generateID(), parent = document.body) {
let element = document.createElement(tagName);
element.id = id;
parent.appendChild( element );
return element;
}
</code></pre>
</section><!-- end ### default parameters ### -->
<!-- ### rest ### -->
<section>
<h1>...rest</h1>
<p class="fragment">is an array of params that were not declared</p>
<p class="fragment">solves the arguments problem</p>
<h2 class="look fragment">＼(｀0´)／</h2>
</section>
<section>
<h2>rest params</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
var sum = function(a, b) {
return a + b;
}
sum(1, 2); // 3
var sum = function(a, b) {
return a + b;
}
sum(1, 2, 3); // ???
var sum = function() {
var args = [].slice.call(arguments);
return args.reduce(function(accu, curr) {
return accu + curr;
}, 0);
}
sum(1, 2, 3, 4, 5) // 15
</code></pre>
<aside class="notes">
sum function with 2 required params ( a, b )
any additional params are optional
</aside>
</section>
<section>
<h2>rest params</h2>
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
var sum = function(...rest) {
return rest.reduce(function(prev, current) {
return prev + current;
}, 0);
}
console.log(sum(1, 2, 3, 4, 5)); // 15
function sum(...rest) {
return rest.reduce((prev, current) => prev + current, 0);
}
console.log(sum(1, 2, 3, 4, 5)); // 15
</code></pre>
</section><!-- end ### rest ### -->
<!-- ### spread ### -->
<section>
<h1>...spread</h1>
<p class="fragment">expands array of args into individual variables</p>
</section>
<section>
<h2>getting the highest value</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
var numbers = [ 0, 20, 22, 42 ];
Math.max.apply(null, numbers); // 42
function sum(x, y, z) {
return x + y + z;
}
sum(numbers[0], numbers[1], numbers[2]); // 42
</code></pre>
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
var numbers = [ 0, 20, 22, 42 ];
Math.max(...numbers); // 42
function sum(x, y, z) {
return x + y + z;
}
sum(...numbers); // 42
</code></pre>
</section>
<section>
<h2>spread array</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
var getCoords = function(x, y, z) {
return {
x: x,
y: y,
z: z
};
}
var points = [ 100, 50, 42 ];
var coords = getCoords(points[0], points[1], points[2]); // { "x": 100, "y": 50, "z": 42 }
</code></pre>
</section>
<section>
<h2>spread array</h2>
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
var getCoords = function(x, y, z) {
return {
x: x,
y: y,
z: z
};
}
var points = [ 100, 50, 42 ];
var coords = getCoords(...points); // { "x": 100, "y": 50, "z": 42 }
var getCoords = function(x, y, z) {
return { x, y, z };
}
var points = [ 100, 50, 42 ];
var coords = getCoords(...points); // { "x": 100, "y": 50, "z": 42 }
var getCoords = (x, y, z) => ({ x, y, z });
var points = [ 100, 50, 42 ];
var coords = getCoords(...points); // { "x": 100, "y": 50, "z": 42 }
var getPoints = ({ x, y, z }) => [ x, y, z];
var coords = getCoords(...getPoints({ "x": 100, "y": 50, "z": 42 })); // { "x": 100, "y": 50, "z": 42 }
</code></pre>
<aside class="notes">
- notice spread into new object literal syntax
</aside>
</section>
<section>
<h2>joining arrays</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
var primes = [ 2, 3, 5 ]
var fibonacci = [ 0, 1, 1 ]
fibonacci = fibonacci.concat( primes ) // [0, 1, 1, 2, 3, 5]
</code></pre>
<div class="fragment">
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
let fibonacci = [ 0, 1, 1, ...primes ]; // [0, 1, 1, 2, 3, 5]
</code></pre>
</div>
</section>
<section>
<h2>joining arrays - advanced</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
var primes = [ 2, 3, 5 ];
var fibonacci = [ 0, 1, 1, 8, 13, 21 ];
primes.forEach(function ( num ) {
var index = fibonacci.indexOf( 8 );
fibonacci.splice( index, 0, num );
})
console.log( fibonacci ); // [0, 1, 1, 2, 3, 5, 8, 13, 21]
</code></pre>
<div class="fragment">
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
let fibonacci = [ 0, 1, 1, ...primes, 8, 13, 21 ];
console.log( fibonacci ); // [0, 1, 1, 2, 3, 5, 8, 13, 21]
</code></pre>
</div>
</section><!-- end ### spread ### -->
<section>
<h2>The rest of new syntax features in part two</h2>
</section>
</section><!-- END OF PART ONE -->
<!-- PART TWO -->
<section>
<section>
<h1>Part two</h1>
<h2>New syntax continues</h2>
</section>
<!-- ### destructuring ### -->
<section>
<h1>destructuring</h1>
<p class="fragment">extract data from objects and arrays</p>
</section>
<section>
<h2>swaping values of variables</h2>
<blockquote>old way</blockquote>
<pre><code data-trim contenteditable>
var a = 1;
var b = 2;
var tmp = a;
a = b;
b = tmp;
</code></pre>
<h2 class="look fragment fade-in">ಠ_ಠ</h2>
</section>
<section>
<h2>swaping values of variables</h2>
<blockquote>new way</blockquote>
<pre><code data-trim contenteditable>
let a = 1;
let b = 2;
let tmp = a;
a = b;
b = tmp;
let [ a, b ] = [ 1, 2 ];
[ a, b ] = [ b, a ];
console.log(a, b); // 2, 1
</pre></code>
<h2 class="look fragment">ʘ‿ʘ</h2>
</section>
<section>
<h2>extract array</h2>
<pre><code data-trim contenteditable>
#008744 (0,135,68) // green
#0057e7 (0,87,231) // blue
#d62d20 (214,45,32) // red
#ffa700 (255,167,0) // orange
#ffffff (255,255,255) // white
let getColors = function() {
return [ '#008744', '#0057e7', '#d62d20' ];
};
let colors = getColors();
let green = colors[0];
let blue = colors[1];
let red = colors[2];
let [ green, blue, red ] = getColors;
console.log(green, blue, red); // "#008744" "#0057e7" "#d62d20"
---