async_sequential.js

const myArray = Array.from({length: 10}, (e, i)=> i)

doWork(
  doSomethingWith,
  myArray,
  logToConsole
)

//Die Funktion, die das Ganze abarbeitet
async function doWork(doSomething, anArray, aCallback) {

  //Mit for(const ... in ...) { ... } geht es
  for(const entry in anArray) {
    await doSomething(entry)
    aCallback(entry)
  }
}

//Hier passiert etwas, was länger dauert
function doSomethingWith(entry) {

  console.log(`handling ${entry}`)

  return new Promise(resolve => setTimeout(resolve, 1000))
}

//Das soll ein callback sein
function logToConsole(value){
  console.log(`done with ${value}`)
  console.log('--------------------')
}