Execute promises map sequentially

Question

I have written a function that is being called in a loop (map) and that function is using promises. Now, I want that function to run synchronously and exit before its next i

Answer 1

Here is what running Promises sequentially would look like when using .reduce() in combination with async/await:

async function main() {

  const t2 = (v) => Promise.resolve(v*2)
  const arr1 = [1,2,3,4,5];
  
  const arr1_mapped = await arr1.reduce(async (allAsync, val) => {
    const all = await allAsync
    all.push(await t2(val) /* <-- your async transformation */) 
    return all
  }, Promise.resolve([]))

  console.log(arr1_mapped)

}

main()