| 53 | {{{ |
| 54 | #!C# |
| 55 | using System.IO; |
| 56 | using System; |
| 57 | |
| 58 | class Program |
| 59 | { |
| 60 | static void Main() |
| 61 | { |
| 62 | Console.WriteLine("Hello, World!"); |
| 63 | Animal animal = new Cat(); |
| 64 | animal.who_am_i(); |
| 65 | animal = new Kitten(); |
| 66 | animal.who_am_i(); |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | abstract class Animal |
| 71 | { |
| 72 | public abstract void who_am_i(); |
| 73 | } |
| 74 | |
| 75 | class Cat:Animal |
| 76 | { |
| 77 | public override void who_am_i() { |
| 78 | Console.WriteLine("I'm a Cat"); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | class Kitten:Cat |
| 83 | { |
| 84 | public override void who_am_i() { |
| 85 | Console.WriteLine("I'm a Kitten"); |
| 86 | } |
| 87 | } |
| 88 | }}} |