Javascript Call and Apply - ES5

js-call-apply.es5.js

function notifyClient(message) {
  alert(message);
}

function sendMail(customer, total) {  
  notifyClient.call(this, 'TODO: Send mail, (' + String(customer.id) + ', ' + String(total) + ')');
}

function getDeals() {  
  var product = arguments[0];
  var minPrice = arguments[1];
  
  product.price = Math.round(product.price * 0.9, 2);
  
  if(product.price < minPrice) {
  	product.price = minPrice;
  }
}

function ShopCart(){
  
}

ShopCart.prototype.items = [];

ShopCart.prototype.customer = { id: 1 };

ShopCart.prototype.total = function total() {
  var total = 0;
  var item;
  
  for(var i=0, c=this.items.length; i<c; i++){
    item = this.items[i];
    total += item.price * item.quantity; 
  }
  
  return total;
};

ShopCart.prototype.addItem =  function addItem(product) {
  this.getDealsByProduct(product);
  this.items.push(product);
  notifyClient.call(this, 'Item added ' + product.name);
};

ShopCart.prototype.getDealsByProduct =  function getDealsByProduct(product) {
  getDeals.apply(this, [product, product.price * 0.6]);
};

ShopCart.prototype.placeOrder =  function placeOrder() {
  sendMail.apply(this, [this.customer, this.total()]);
};

var shopCart = new ShopCart();

shopCart.addItem({
  id: 1,
  name: 'Xbox Game',
  price: 179,
  quantity: 1
});

shopCart.placeOrder();