JS
What’s new in JavaScript
ES2021
Gaute Meek Olsen
JS
What’s new in JavaScript
ES2021
1
Gaute Meek Olsen
2
JavaScript created 1995
Standarized by ECMAScript
| Year | Edition | Community Name | Official Name |
|---|---|---|---|
| 1997 | 1 | ||
| 1998 | 2 | ||
| 1999 | 3 | ES3 | |
| Abandond | 4 | ES4 | |
| 2009 | 5 | ES5 | |
| 2011 | 5.1 | ||
| 2015 | 6 | ES6 | ES2015 |
| 2016 | 7 | ES7 | ES2016 |
| 2017 | 8 | ES8 | ES2017 |
| 2018 | 9 | ES9 | ES2018 |
| 2019 | 10 | ES10 | ES2019 |
| 2020 | 11 | ES11 | ES2020 |
| 2021 | 12 | ES12 | ES2021 |
| Future | ESNext |
3
Numeric separators
const hardToRead = 1000000000;
4
replaceAll
const apples = '🍏🍏🍏';
const oranges = apples.replace('🍏', '🍊');
console.log(oranges)
5
Promise.any
const slow = () => new Promise(resolve => {
setTimeout(() => resolve('slow'), 2_000);
});
const fast = () => new Promise(resolve => {
setTimeout(() => resolve('fast'), 500);
});
const fail = () => new Promise((_, reject) => reject('nope'));
const promises = [
slow(),
fast(),
fail(),
];
const result = await Promise.race(promises);
console.log(result);
6
Logical assignment
let x = 0
// && - truthy
// || - falsy
// ?? - nullish
console.log(x)
7
WeakRef
const cacheRef = new WeakRef({ count: 0 });
8
The End... Thank You For Listening!
9