Gain insights into JavaScript from basics to ES2021, delve into TypeScript essentials, and test your knowledge through quizzes and coding challenges to reinforce learning.

node.tar.gz

node:latest

Jan/2021 Updated to include ES2021

Whether you are a complete beginner or you have some knowledge of JavaScript, this course will guide you from the basics of the language to all the new features introduced up until 2021.  You’ll test your knowledge with quizzes and some coding challenges at the end of each chapter. 

After following this course, the functions and variables let, const, generators, promises and async won't be a problem anymore.

If you want to experience something new, this course also includes an introduction to the basics of TypeScript, which is a must-know for any JavaScript developer.

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The Complete Guide to Modern JavaScript

# `Array.from()`

`Array.from()` is the first of many new array methods that ES6 introduced.

It will take something arrayish- meaning something that looks like an array but isn’t- and transform it into a real array.

Look at the code in the JavaScript and the HTML tab to see what is happening.

<html>
 <head>
 </head>
 <body>
   <div class="fruits">
    <p>Apple</p>
    <p>Banana</p>
    <p>Orange</p>
  </div>
 </body>
</html>

document.addEventListener("DOMContentLoaded", function () {
  const fruits = document.querySelectorAll(".fruits p");
// fruits is a nodelist (an array-like collection) containng our three p tags
// now we convert it in an Array
const fruitArray = Array.from(fruits);

console.log(fruitArray);
// [p,p,p]

//since now we are dealing with an array we can use map
const fruitNames = fruitArray.map( fruit => fruit.textContent);

console.log(fruitNames);
// ["Apple", "Banana", "Orange"]
});

codemirror

console

document.addEventListener("DOMContentLoaded", function () {
const fruits = Array.from(document.querySelectorAll(".fruits p"));
const fruitNames = fruits.map(fruit => fruit.textContent);

console.log(fruitNames);
// ["Apple", "Banana", "Orange"]
});



Now we transformed **fruits** into a real array, meaning that we can use any sort of method such as `map` on it.

`Array.from()` also takes a second argument, a `map` function so we can write:

This lesson covers the new methods to create and handle Array in ES6.

Introduction

Intro To JavaScript

ES6

From ES2016 to ES2022

Intro To TypeScript

Appendix

Array Improvements