async await js

1(async () => {
2  let response = await fetch('/article/promise-chaining/user.json');
3  let user = await response.json();
4  ...
5})();

1// Old School Javascript Invoke
2(async function() {
3	await someAsyncFunction();
4})();
5
6//New ES6 Javascript Invoke
7(async () => {
8	await someAsyncFunction();
9})();

1const data = async ()  => {
2  const got = await fetch('https://jsonplaceholder.typicode.com/todos/1');
3  
4  console.log(await got.json())
5}
6
7data();

1async function showAvatar() {
2
3  // read our JSON
4  let response = await fetch('/article/promise-chaining/user.json');
5  let user = await response.json();
6
7  // read github user
8  let githubResponse = await fetch(`https://api.github.com/users/${user.name}`);
9  let githubUser = await githubResponse.json();
10
11  // show the avatar
12  let img = document.createElement('img');
13  img.src = githubUser.avatar_url;
14  img.className = "promise-avatar-example";
15  document.body.append(img);
16
17  // wait 3 seconds
18  await new Promise((resolve, reject) => setTimeout(resolve, 3000));
19
20  img.remove();
21
22  return githubUser;
23}
24
25showAvatar();

1function resolveAfter2Seconds() {
2  return new Promise(resolve => {
3    setTimeout(() => {
4      resolve('resolved');
5    }, 2000);
6  });
7}
8
9//async function:
10async function asyncCall() {
11  console.log('calling');
12  const result = await resolveAfter2Seconds();
13  console.log(result);
14  // expected output: 'resolved'
15}
16
17asyncCall();

1fetch('coffee.jpg')
2.then(response => {
3  if (!response.ok) {
4    throw new Error(`HTTP error! status: ${response.status}`);
5  } else {
6    return response.blob();
7  }
8})
9.then(myBlob => {
10  let objectURL = URL.createObjectURL(myBlob);
11  let image = document.createElement('img');
12  image.src = objectURL;
13  document.body.appendChild(image);
14})
15.catch(e => {
16  console.log('There has been a problem with your fetch operation: ' + e.message);
17});