javascript async/await not working

Question

I have a specific case where I need to wait for a async calls result before continuing. I am using the async/await keywords, but not having any luck. Any help appreciated.

This is my attempt to try getting it to work, the numbers should be in numerical order.

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function demo() {
  document.writeln('2...');
  await sleep(2000);
  document.writeln('3...');
}

document.writeln('1...');
demo();
document.writeln('4.');

Answer 1

The async function will return a Promise, so you need to await the call to demo

const sleep = (ms) => new Promise(resolve => setTimeout(resolve, ms))

const demo = async() => {
  console.log('2...')
  await sleep(2000)
  console.log('3...')
}

const blah = async() => {
  console.log('1...')
  await demo()
  console.log('4.')
}

blah()

Answer 2

You should use .then() after async function.

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

async function demo() {
  document.writeln('2...');
  await sleep(2000);
  document.writeln('3...');
}

document.writeln('1...');
demo().then(() => {
    document.writeln('4.');
});