static void Main(string[] args)
{
//
// OLD MACDONALD
//
Console.WriteLine("Old MacDonald had a farm ee ay ee ay oh");
//ISingable sing = new ISingable(); CANNOT instantiate an interface
// Let's try singing about a Farm Animal
List <ISingable> itemsOnTheFarm = new List <ISingable>();
itemsOnTheFarm.Add(new Horse());
itemsOnTheFarm.Add(new Goat());
itemsOnTheFarm.Add(new Elephant());
itemsOnTheFarm.Add(new Snake());
itemsOnTheFarm.Add(new Tractor());
//itemsOnTheFarm.Add(new Apple()); //Apple does NOT implement the ISingable interface, we can't add it to a a list of ISingables
if (itemsOnTheFarm[0] is FarmAnimal)
{
FarmAnimal animal = (FarmAnimal)itemsOnTheFarm[0];
animal.GoToSleep();
}
// write a foreach loop to sing the verse about ever animal in the List
foreach (ISingable item in itemsOnTheFarm)
{
SingTheVerse(item);
}
// What if we wanted to sing about other things on the farm that were
// singable but not farm animals?
// Can it be done?
List <ISellable> yardSale = new List <ISellable>();
foreach (ISingable item in itemsOnTheFarm)
{
if (item is ISellable) //just showing you...avoid this
{
yardSale.Add((ISellable)item);
}
}
yardSale.Add(new Apple());
Dictionary <int, ISellable> yardSaleLocations = new Dictionary <int, ISellable>();
yardSaleLocations.Add(1, new Apple()); //in stall one there are apples for sale
yardSaleLocations.Add(2, new Elephant()); //in stall number 2 there is an elephant for sale
//print the sellable things
//for your exercises, you are supposed to line things up
Console.WriteLine("Sellable stuff\n\n");
Console.WriteLine("{0,15} {1,5}", "Name", "Price");
foreach (ISellable item in yardSale)
{
Console.WriteLine("{0,15} {1,-5:C}", item.Name, item.Price);
}
Console.ReadLine();
}