CODEWITHSUNDEEP
javascriptarrayspromise
ms_nitrogen
ms_nitrogen

Reputation: 240

How to map an array of strings for a Promise.all argument?

What I am looking to do is to use an array of strings to use those values to map a new array of promise functions for a Promise.all argument.

I think explains my thought process so far, as well as the issue I am running into.

const strings = ['A', 'B', 'C'] // Varies in size
const stringFunctions = strings.map(item => {
  const func = () => {
    promised(item) // Returns Promised Boolean
  }
  return func
})

const PromiseAll = new Promise(function(resolve, reject) {
  Promise.all(stringFunctions)
    .then(items => {
      const obj = {};
      items.forEach((item, index) => {
        obj[strings[index]] = item;
      });
      resolve(obj); 
      // returns { A: func(), B: func(), C: func() }
      // expected { A: bool, B: bool, C: bool }
    })
    .catch(error => {
      reject(error);
    });
}

Upvotes: 2

Views: 1539

Answers (1)

danh
danh

Reputation: 62676

This can be done without any explicit promise creation (you have all you need in the promised function and in Promise.all()).

let strings = [ ... ]
let promises = strings.map(string => promised(string));
Promise.all(promises).then(results => {
    // results is a new array of results corresponding to the "promised" results
});

Upvotes: 2

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