JSON Stringify is making an object key with a value of array of objects empty

Question

Can someone help me with this, I am trying to achieve an object like so:

{ "docs": [
{ "_id": "item" },
{ "_id": "item" },
{ "_id": "item" }
] }

So I begin with having an object with a key docs which is an array I will push into

let query = { docs: [] };

i then have list of key value pair items like so, around 80:

{ _id: item }

which i push into docs in a forEach loop

 query.docs.push(item);

So when I go and stringify

JSON.stringify(query);

it returns the object but the array is empty.

{ "docs": [] }

I’ve no idea why this is happening. Anyone know an approach to go around this to achieve the desired result? Thanks in advance

Actual code:

let elasticQuery = {
    docs: []
  };

  axios({
    method: "post",
    headers: {
      "Content-Type": "application/json"
    },
    url: sent2VecUrl,
    data: {
      selected_text: query
    }
  }).then(results => {
    results.data.response.forEach(item => {
      elasticQuery.docs.push({ _id: item });
    });
  });


  console.log("without: " + elasticQuery + " with stringify :" + JSON.stringify(elasticQuery));

This is the server response:

The problem is that JSON.stringify(elasticQuery) is executed before results.data.response.forEach......, before you push values into the elasticQuery.docs array. — Titus
– Titus, Commented Aug 16, 2018 at 12:12

Sagar Kharche · Accepted Answer · 2018-08-16 12:14:38Z

3

Move your console in .then function. This is asyn call and your console is printing before your promise is getting resolved.

axios({
method: "post",
headers: {
  "Content-Type": "application/json"
},
url: sent2VecUrl,
data: {
  selected_text: query
}})
.then(results => {
   results.data.response.forEach(item => {
      elasticQuery.docs.push({ _id: item });
   });
   console.log("without: " + elasticQuery + " with stringify :" + JSON.stringify(elasticQuery));
});

answered Aug 16, 2018 at 12:14

Sagar Kharche

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2 Comments

NewScientists Over a year ago

Thanks, i moved the console.log to that position and it indeed showed changes, i completely missed the async aspect.

NewScientists Over a year ago

There was a guy who posted the answer but then deleted it before i could accept :( anyway i think it works now

Saurabh Yadav · Accepted Answer · 2018-08-16 12:14:46Z

0

You code looks fine.

.then(results => {
    results.data.response.forEach(item => {
      elasticQuery.docs.push({ _id: item });
    });

      console.log(elasticQuery); 
  });

answered Aug 16, 2018 at 12:14

Saurabh Yadav

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Comments

Alex Alexiuc · Accepted Answer · 2018-08-16 12:17:41Z

0

instead of this:

results.data.response.forEach(item => {
      elasticQuery.docs.push({ _id: item });
});

do this:

  elasticQuery.docs = results.data.response.map(item => ({ _id: item }) )

answered Aug 16, 2018 at 12:17

Alex Alexiuc

831 silver badge10 bronze badges

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