Async function is a function that returns Promise. The benefit is, it makes code more readable.
The goal of async is to make the code look synchronous, an asynchronous code look synchronous.
Async Await are just promises under neat the hood, we called it syntactic sugar.
EX 1:
async function playerStart() {
const firstMove = await move(400, 'Left');
await move(400, 'Right');
await move(400, 'Up');
await move(400, 'Down');
}
EX 2:
// Basic usage
fetch('https://jsonplaceholder.typicode.com/users')
.then(res => res.json())
.then(console.log);
// using ASYNC AWAIT
async function getUsers() {
const res = await fetch('https://jsonplaceholder.typicode.com/users')
const data = await res.json();
console.log(data); // response
}
EX 3:
const urls = [
'https://jsonplaceholder.typicode.com/users',
'https://jsonplaceholder.typicode.com/posts',
'https://jsonplaceholder.typicode.com/albums'
];
// Basic usage
Promise.all(urls.map(url => {
fetch(url).then(res => res.json());
}))
.then(array => {
console.log('users', array[0]);
console.log('posts', array[1]);
console.log('albums', array[2]);
})
.catch(console.log);
// using ASYNC AWAIT
const getDatas = async function() {
try {
const [users, posts, albums] = await Promise.all(urls.map(url => {
return fetch(url).then(res => res.json());
}));
console.log('users', users);
console.log('posts', posts);
console.log('albums', albums);
} catch(err) {
console.log(err);
}
}
getDatas();
