How can I return a value from .then method of a promise?

Question

In the following javascript code snippet (written for nodejs), the createDoc function returns a promise. Upon fulfillment of the promise, the handler passed to .then is invoked. The question is that how can I make .then return doc? According to the documentation, .then returns a promise but I'm really looking for it to return doc.

 let p = createDoc(title).then(function (doc) {return doc;});

 //p is a promise, and not doc
 console.log(p);

What is the proper way to access the value passed to the fulfillment handler (doc in this case) outside the .then?

In promise, you always get a promise in return. What you are going to do with `doc` - that will give some idea on how to proceed. — Nishant, Jun 05 '20 at 06:09

score 1 · Answer 1 · answered Jun 05 '20 at 06:06

1

do something like this and when the promise resolves the value of doc will be inside p

let p;
createDoc(title).then(doc => p = doc);

answered Jun 05 '20 at 06:06

arnavpanwar99

377
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6

@Nishant yeah but that's what he want, he wants the resolved value in p – arnavpanwar99 Jun 05 '20 at 06:15
And can you access p after createDoc – Shubham Khatri Jun 05 '20 at 06:23

score 0 · Answer 2 · answered Jun 05 '20 at 06:05

0

You can use async-await, if you want to have the value instead of promise in p

async function someFunction() {
    ...
    let p = await createDoc(title);
     console.log(p);

    ...
}

What you are seeing is a behavior of promises calling chaining.

answered Jun 05 '20 at 06:05

Shubham Khatri

270,417
55
406
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How can I return a value from .then method of a promise?

2 Answers2