public static void Print(FatCat c)
{
if (c == null)
{
Console.WriteLine("Fat cat was null?");
return;
}
Console.WriteLine("Fat cat has a width of " + c.FatnessWidth);
}
static void Main(string[] args)
{
// Making a few cats and treating them as ICat
// This is good for a demonstration, but in real life generally you won't do this
ICat fatCat = new FatCat();
ICat shortCat = new ShortCat();
fatCat.Meow();
shortCat.Meow();
// Since we know we have a fat cat, we can use our fat cat printer
FatCat castFatCat = fatCat as FatCat;
FatCatPrinter.Print(castFatCat);
// What happens if we cast our ShortCat as a FatCat?
FatCat castShortCat = shortCat as FatCat;
FatCatPrinter.Print(castShortCat);
// What would happen if we didn't use the "as" keyword?
// FatCatPrinter.Print((FatCat)shortCat);
// What's the advantage of using "as" ?
// We can do null checks
//FatCat castShortCat2 = shortCat as FatCat;
//if (castShortCat2 != null)
// FatCatPrinter.Print(castShortCat2);
// The "is" keyword is similar to as, but only returns true/false
if (shortCat is FatCat)
{
FatCatPrinter.Print((FatCat)shortCat);
}
Console.WriteLine("---");
Console.WriteLine("--- Now using factory ---");
Console.WriteLine("---");
// More realistic example of getting cats
ICat catFromFactory1 = CatFactory.GetCat();
ICat catFromFactory2 = CatFactory.GetCat();
catFromFactory1.Meow();
catFromFactory2.Meow();
// Assignment
//
// todo: Use both keywords "as" and "is" to safely call the FatCatPrinter.Print method
//
}
