Wait for a setTimeout() to finish to continue processing

Question

I need to loop through an array reading each element after some time, the only solution I've seen is to use setTimeOut() in Typescript.

The problem is that I need the function to finish to continue the process.

This is what I currently have:

async function testData() {

  let arrT = ['data1','data2','data3']
  let countReq = 0
  let result = []
  for await (let getA of arrT) {

    countReq++
    setTimeout(async() => {
      result.push(
        `test - ${getA}`
      )
    }, countReq * 1000)

  }

  console.log(result)
  return result;

}
testData()

Now it returns the empty array because the process has not finished, I need to wait and return the array with the complete information

I don't know if using setTimeout() in this case is the best option, I don't know if there is a better way to do this.

Wrap the setTimeout in a promise which you can await. – tkausl Dec 22 '22 at 23:47 — tkausl, Dec 22 '22 at 23:47

Nora Söderlund · Answer 1 · 2022-12-22T23:55:48.113

1

You can use a Promise to resolve the task with await. You don't need to provide await after your for key.

function sleepTimeout(interval) {
  return new Promise((resolve) => {
    setTimeout(resolve, interval);
  });
};

async function testData() {

  let arrT = ['data1','data2','data3']
  let countReq = 0
  let result = []
  for (let getA of arrT) {
    countReq++

    await sleepTimeout(1000);
    
    result.push(`test - ${getA}`);
  }

  console.log(result)
  return result;

}
testData()

edited Dec 22 '22 at 23:55

answered Dec 22 '22 at 23:48

Nora Söderlund

1,148
2
18

I had not tried with promise, I thought that the setTimeOut could do it alone. I need to multiply it by 1000 because if it takes less time the process breaks – mikestr Dec 22 '22 at 23:58

Wait for a setTimeout() to finish to continue processing

1 Answers1