Using promise for an object

Question

Is there anyway to use promise for object iteration? Here's my source code.

 Object.keys(drop).map((key) => {
            RNGooglePlaces.lookUpPlaceByID(drop[key].placeID)
              .then((results) => {
                results.t = results.address;
                results.l = `${results.latitude},${results.longitude}`;
                array.push(results);
              })
              .catch((error) => reject(error));
 });
        console.log(JSON.stringify(array));

This code above is not working because I have used Promise in object.keys.map function.

For getting the correct result of array, I think I have to use Promise for Object.map

I have used PromiseArrays for promise iteration but it doesn't work.

Is there any best solution?

Answer 1

Note, no value is returned from .map() and console.log(array) is called outside of Promise chain. You can use Promise.all() and return a value from .map() to get an array of fulfilled Promise objects at .then()

 let promises = Promise.all(
                  Object.keys(drop).map(key => 
                    RNGooglePlaces.lookUpPlaceByID(drop[key].placeID)
                    .then(results => {
                      results.t = results.address;
                      results.l = `${results.latitude},${results.longitude}`;
                      return results;
                    })
                  )
                );
 promises.then(results => console.log(results))
 .catch(error => console.error(error));