how to write an async function javascript code example
Example 1: how to make an async function
function resolveAfter2Seconds() {
return new Promise(resolve => {
setTimeout(() => {
resolve('resolved');
}, 2000);
});
}
//async function:
async function asyncCall() {
console.log('calling');
const result = await resolveAfter2Seconds();
console.log(result);
// expected output: 'resolved'
}
asyncCall();
Example 2: 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;
}