I'm trying async/await functionality. I have such code imitating a request:
const getJSON = async () => {
const request = () => new Promise((resolve, reject) => (
setTimeout(() => resolve({ foo: 'bar'}), 2000)
));
const json = await request();
return json;
}
When I use the code in this way
console.log(getJSON()); // returns Promise
it returns a Promise
but when I call this line of code
getJSON().then(json => console.log(json)); // prints { foo: 'bar' }
it prints json as expected
Is it possible to use just code like console.log(getJSON())
? What don't I understand?
Every async
function returns a Promise
object. The await
statement operates on a Promise
, waiting until the Promise
resolve
s or reject
s.
So no, you can't do console.log
on the result of an async function directly, even if you use await
. Using await
will make your function wait and then return a Promise
which resolves immediately, but it won't unwrap the Promise
for you. You still need to unwrap the Promise
returned by the async
function, either using await
or using .then()
.
When you use .then()
instead of console.log
ging directly, the .then()
method makes the result of the Promise available to you. But you can't get the result of the Promise
from outside the Promise. That's part of the model of working with Promises.