CompleteNodeJS/playground/4-callbacks.js

const doWorkCallback = (callback) => {
  setTimeout(() => {
    //callback('This is my error!', undefined)
    callback(undefined, [1, 4, 7])
  }, 2000)
}

doWorkCallback((error, result) => {
  if (error) {
    return console.log(error)
  }

  console.log(result)
})