NodeJS: non-blocking I/O

restaurant.js

// understanding the Event Loop and async nature of nodejs
// resource help from : https://www.codeschool.com/blog/2014/10/30/understanding-node-js/
function submitOrder(orderNumber){
  console.log('Submitted order and cooking: ' + orderNumber)
  cookingFood(function afterEvent(){
    console.log('food is cooked and ready to be delivered')
  })
}

// 5s operation
function cookingFood(cb){
  setTimeout(cb,5000)
}

submitOrder(1)
submitOrder(2)
submitOrder(3)