Array keep empty after push object from forEach

Question

Need Help, I have problem Array Keep Empty After pushing object from forEach, do I miss something ? here's the code :

const allStatus = [];
    result.forEach(async (element) => {
      const count = await BpCandidate.count({
        where: {
          applicationStatusId: element.id
        },
        raw: true,
      });
      })  
      record = {
        id: element.id,
        name: element.name,
        code: element.code,
        description: element.description,
        total: count
      };
      allStatus.push(record);
    });
    console.log(allStatus);

Thanks in advance

yes I Get the output for result @RajaShekar, but for the allStatus it's empty array only [] — , Jun 09 '20 at 04:38
Does this answer your question? [Using async/await with a forEach loop](https://stackoverflow.com/questions/37576685/using-async-await-with-a-foreach-loop) — Matt, Jun 09 '20 at 04:55
`result.forEach` doesn't wait for the async functions to resolve. — Matt, Jun 09 '20 at 04:56
Also bluebird provides useful array helpers like [.map](http://bluebirdjs.com/docs/api/promise.map.html) — Matt, Jun 09 '20 at 05:02
Thanks for help @Matt im using ```for … of```` it's now working — , Jun 09 '20 at 05:03

Tony Nguyen · Accepted Answer · 2020-06-09T06:01:05.323

2

Using for...of is working for you, but can see an improvement here if you use Promise.all

const allStatus = await Promise.all(result.map(async (element) => {
  const count = await BpCandidate.count({
    where: {
      applicationStatusId: element.id
    },
    raw: true,
  });
  return  {
    id: element.id,
    name: element.name,
    code: element.code,
    description: element.description,
    total: count
  };
}))

edited Jun 09 '20 at 06:01

answered Jun 09 '20 at 05:14

Tony Nguyen

3,298
11
19

@NelvanBalthazar My bad, forgot to update to use `map` instead of `forEach`. Please check my updated comment. – Tony Nguyen Jun 09 '20 at 06:01

score 1 · Answer 2 · edited Jun 09 '20 at 14:19

first you need to define element variable in outer scope of foreach part to get the desired result, here is the helper code snippet:

    const allStatus = [];
    result.forEach(async (element) => {
      const count = await BpCandidate.count({
        where: {
          applicationStatusId: element.id
        },
        raw: true,
      });
      record = {
        id: element.id,
        name: element.name,
        code: element.code,
        description: element.description,
        total: count
      };
      allStatus.push(record);
      })  
    });
    console.log(allStatus);

score 1 · Answer 3 · answered Jun 09 '20 at 05:33

for each doesn't perform async task and doesn't resolve promises. Use for of or Promise.All the loop iterations.

const allStatus = [];
for(let element of result) {
  const count = await BpCandidate.count({
    where: {
      applicationStatusId: element.id
    },
    raw: true,
  });
  })  
  record = {
    id: element.id,
    name: element.name,
    code: element.code,
    description: element.description,
    total: count
  };
  allStatus.push(record);
});
console.log(allStatus);

Array keep empty after push object from forEach

3 Answers3

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