await javascript example

Example 1: async await

async function showAvatar() {

  // read our JSON
  let response = await fetch('/article/promise-chaining/user.json');
  let user = await response.json();

  // read github user
  let githubResponse = await fetch(`https://api.github.com/users/${user.name}`);
  let githubUser = await githubResponse.json();

  // show the avatar
  let img = document.createElement('img');
  img.src = githubUser.avatar_url;
  img.className = "promise-avatar-example";
  document.body.append(img);

  // wait 3 seconds
  await new Promise((resolve, reject) => setTimeout(resolve, 3000));

  img.remove();

  return githubUser;
}

showAvatar();

Example 2: await javascript

The await operator is used to wait for a Promise. It can only be used inside an async function within regular JavaScript code; however it can be used on its own with JavaScript modules.

Example 3: async await js

fetch('coffee.jpg')
.then(response => {
  if (!response.ok) {
    throw new Error(`HTTP error! status: ${response.status}`);
  } else {
    return response.blob();
  }
})
.then(myBlob => {
  let objectURL = URL.createObjectURL(myBlob);
  let image = document.createElement('img');
  image.src = objectURL;
  document.body.appendChild(image);
})
.catch(e => {
  console.log('There has been a problem with your fetch operation: ' + e.message);
});

Example 4: await javascript

If the value of the expression following the await operator is not a Promise, it's converted to a resolved Promise.