Re-factor the code in a functional-programming way

shopping-cart.js

var shoppingCartTotalPrice = (function(){

  var items = [
 	  {
		  name:'Domus IPA',
		  amount:3,
		  unitPrice:2.5,
	  },
	  {
		  name:'Cibeles',
		  amount:6,
		  unitPrice:2.0
	  },
	  {
		  name:'La Victoria',
		  amount:2,
		  unitPrice:1.35
	  }
  ];


  return (
  	function(){
  		var totalPrice  = 0;
  		for(var itemIndex=0;itemIndex<items.length;itemIndex++){
        		var item = items[itemIndex];
  			totalPrice+= (item.amount*item.unitPrice)
  		}
  		return totalPrice;
  	}()
  );

})();


console.log(shoppingCartTotalPrice);