In addition to passing interface variables into a method as parameters, you can also pass an interface back as the return value of a method.
In the example below, we define a method that looks through an array of objects and returns the first object found that implements the IMoo interface.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | static IMoo FindAMooer(object[] candidates){ IMoo theMooer = null; foreach (object candidate in candidates) { if (candidate is IMoo) { theMooer = (IMoo)candidate; break; // stop looking } } return theMooer;} |
We can then pass in any array of objects to this method and the method will find the first one that can moo.
1 2 3 4 5 | Cow bessie = new Cow("Bessie", 4);Dog spike = new Dog("Spike", 5);IMoo mooer = FindAMooer(new object[] { spike, 42, "Jude", bessie });mooer.Moo(); |
