how to use async await nodejs code 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: js async await
/* Notes:
1. written like synchronous code
2. compatible with try/catch blocks
3. avoids chaining .then statements
4. async functions always return a promise
5. function pauses on each await expression
6. A non promise value is converted to
Promise.resolve(value) and then resolved
*/
// Syntax
// Function Declaration
async function myFunction(){
await ... // some code goes here
}
// Arrow Declaration
const myFunction2 = async () => {
await ... // some code goes here
}
// OBJECT METHODS
const obj = {
async getName() {
return fetch('https://www.example.com');
}
}
// IN A CLASS
class Obj {
// getters and setter CANNOT be async
async getResource {
return fetch('https://www.example.com');
}
}
Example 3: 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 4: await async
function afterPrintSave() {
Xrm.Page.data.save().then(
function () {
resolve();
},
function (err) {
resolve(alert(err.message));
}
);
}