gistfile1.txt

<script>
  // First log 'start'
  // Then log "starting alpha"
  // Then, sleep for 2 seconds
  // Then, log 'alpha'
  // Then, log "starting beta"
  // Then, 4 seconds later, log beta
  // Then, log "starting gamma"
  // Then, 1 second later log gamma
  // Then, log "starting delta"
  // Then, 3 seconds later log delta
  console.log('start')
  function sleep (milliseconds) {
    return new Promise((resolve) => {
      setTimeout(() => {
        resolve()
      }, milliseconds)
    })
  }
  async function main () {
    console.log('starting alpha')
    await sleep(2000) // blocking
    console.log('alpha')
    console.log('starting beta')
    await sleep(4000)
    console.log('beta')
    console.log('starting gamma')
    await sleep(1000)
    console.log('gamma')
    console.log('starting delta')
    await sleep(3000)
    console.log('delta')
  }
  main() // asynchronous / non-blocking
  console.log('after')
</script>