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

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();

1function hello() {
2  return new Promise((resolve,reject) => {
3    setTimeout(() => {
4      resolve('I am adam.');
5    }, 2000);
6  });
7}
8async function async_msg() {
9  try {
10    let msg = await hello();
11    console.log(msg);
12  }
13  catch(e) {
14    console.log('Error!', e);
15  }
16}
17async_msg(); //output - I am adam.

1async function f() {
2
3  try {
4    let response = await fetch('/no-user-here');
5    let user = await response.json();
6  } catch(err) {
7    // catches errors both in fetch and response.json
8    alert(err);
9  }
10}
11
12f();

1function delayResult() {
2 return new Promise(resolve => {
3   setTimeout(() => {
4     resolve(‘Done’);
5   }, 5000)
6 })
7}
8async function getResult() {
9 let result = await delayResult();
10 return result;
11}
12getResult();