Pro C# 2010 and the .NET 4 Platform, Fifth Edition

9.3. Implementing an Interface

When a class (or structure) chooses to extend its functionality by supporting interfaces, it does so using a comma-delimited list in the type definition. Be aware that the direct base class must be the first item listed after the colon operator. When your class type derives directly from System.Object, you are free to simply list the interface(s) supported by the class, as the C# compiler will extend your types from System.Object if you do not say otherwise. On a related note, given that structures always derive from System.ValueType (see Chapter 4 for full details), simply list each interface directly after the structure definition. Ponder the following examples:

// This class derives from System.Object and // ...