Filtering an array with a function that returns a promise

Question

Given

let arr = [1,2,3];

function filter(num) {
  return new Promise((res, rej) => {
    setTimeout(() => {
      if( num === 3 ) {
        res(num);
         


        

Answer 1

A valid way to do this (but it seems too messy):

let arr = [1,2,3];

function filter(num) {
  return new Promise((res, rej) => {
    setTimeout(() => {
      if( num === 3 ) {
        res(num);
      } else {
        rej();
      }
    }, 1);
  });
}

async function check(num) {
  try {
    await filter(num);
    return true;
  } catch(err) {
    return false;
  }
}

(async function() {
  for( let num of arr ) {
    let res = await check(num);
    if(!res) {
      let index = arr.indexOf(num);
      arr.splice(index, 1);
    }
  }
})();

Again, seems way too messy.