Node js return not returning anything

Question

I'm trying to recover the value of a function but it doesn't returns anything

This is the function (Request is an async function that makes a get petition):

var getVolumesOKCoin = function(pair){
  request('https://www.okcoin.com/api/v1/depth.do?symbol=' + pair, function (error, response, body) {
    return body;
  });
}

And this is how I recover the value

var  retObj = getVolumesOKCoin(pair);

The value of retObj is undefined.

What is the best way to recover the value?

Thanks for your help.

Sorry about the names of the functions, they are the same in my code, I edited to simplify the question — Enrique Alcazar, Aug 19 '17 at 18:11

lumio · Accepted Answer · 2017-08-19T18:21:08.193

3

First things first: your function is called getVolumesOKCoin and not getVolumes.

But still your function won't return anything, because you are calling an async function that needs some time to receive data before returning it. See this question here about how asynchronous calls work.

One solution would be to wrap your function body inside a so called Promise and resolve it as soon as data was received.

var getVolumesOKCoin = function(pair) {
  return new Promise( ( resolve, reject ) => {
    request('https://www.okcoin.com/api/v1/depth.do?symbol=' + pair, (error, response, body) => {
      resolve( body );
    } );
  } );
}

getVolumesOKCoin()
  .then( ( body ) => {
    console.log( body );
  } )
  .catch( ( err ) => {
    console.error( 'Error!' );
  } );

Also make sure, request is defined.

edited Aug 19 '17 at 18:21

answered Aug 19 '17 at 18:07

lumio

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*"that's why you get undefined."* No, that's not the case. If the name was really incorrect, then they would get a `ReferenceError`. – Felix Kling Aug 19 '17 at 18:11
@FelixKling you are right. Thanks for pointing it out. – lumio Aug 19 '17 at 18:21
@lumio Works perfectly, and the comment about the undefined was done after your solution my bad not yours – Enrique Alcazar Aug 19 '17 at 18:25

score 0 · Answer 2 · answered Aug 19 '17 at 18:11

0

Simple add return to the request.

var getVolumesOKCoin = function(pair){
  return request('https://www.okcoin.com/api/v1/depth.do?symbol=' + pair, function (error, response, body) {
    return body;
  });
}

answered Aug 19 '17 at 18:11

underscore

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Are you sure this will work? What does `request` return? – Felix Kling Aug 19 '17 at 18:12

Node js return not returning anything

2 Answers2