Data encapsulation with closure

index.js

const monitorProductivityTime = () => {
  let timeWithoutReset = 0;
  const productivityTime = () => timeWithoutReset++;
  const totalProductivityTime = () => timeWithoutReset;
  const reset = () => {
    timeWithoutReset = -1;
    return 'production time has been restarted!';
  }

  setInterval(productivityTime, 1000);
  return {
    totalProductivityTime, 
    reset
  }
}

const holdTime = monitorProductivityTime();

holdTime.totalProductivityTime();