js async await node js code example
Example 1: 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 2: javascript async await
// The await operator in JavaScript can only be used from inside an async function.
// If the parameter is a promise, execution of the async function will resume when the promise is resolved
// (unless the promise is rejected, in which case an error will be thrown that can be handled with normal JavaScript exception handling).
// If the parameter is not a promise, the parameter itself will be returned immediately.[13]
// Many libraries provide promise objects that can also be used with await,
// as long as they match the specification for native JavaScript promises.
// However, promises from the jQuery library were not Promises/A+ compatible until jQuery 3.0.[14]
async function createNewDoc() {
let response = await db.post({}); // post a new doc
return await db.get(response.id); // find by id
}
async function main() {
try {
let doc = await createNewDoc();
console.log(doc);
} catch (err) {
console.log(err);
}
}
main();