async await in javascript example
Example 1: async await
const data = async () => {
const got = await fetch('https://jsonplaceholder.typicode.com/todos/1');
console.log(await got.json())
}
data();
Example 2: 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 3: async await javascript
function hello() {
return new Promise((resolve,reject) => {
setTimeout(() => {
resolve('I am adam.');
}, 2000);
});
}
async function async_msg() {
try {
let msg = await hello();
console.log(msg);
}
catch(e) {
console.log('Error!', e);
}
}
async_msg(); //output - I am adam.
Example 4: javscript async await explained
// Promise approach
function getJSON(){
// To make the function blocking we manually create a Promise.
return new Promise( function(resolve) {
axios.get('https://tutorialzine.com/misc/files/example.json')
.then( function(json) {
// The data from the request is available in a .then block
// We return the result using resolve.
resolve(json);
});
});
}
// Async/Await approach
// The async keyword will automatically create a new Promise and return it.
async function getJSONAsync(){
// The await keyword saves us from having to write a .then() block.
let json = await axios.get('https://tutorialzine.com/misc/files/example.json');
// The result of the GET request is available in the json variable.
// We return it just like in a regular synchronous function.
return json;
}
Example 5: async and await
function delayResult() {
return new Promise(resolve => {
setTimeout(() => {
resolve(‘Done’);
}, 5000)
})
}
async function getResult() {
let result = await delayResult();
return result;
}
getResult();
Example 6: async await javascript
myFunction().then(
function(value) { /* code if successful */ },
function(error) { /* code if some error */ }
);