Microsoft Certified Solutions Developer (MCSD) Certification Practice Test

Why would you use an explicit interface implementation?

1. To simplify inheritance hierarchies

2. To expose all interface members publicly

3. To avoid naming collisions in interfaces

4. To enforce contract on public methods

The correct answer is: To avoid naming collisions in interfaces

Using an explicit interface implementation is particularly beneficial in scenarios where there may be naming collisions between members of different interfaces. When a class implements multiple interfaces that contain members with the same name, an explicit interface implementation allows you to provide distinct implementations for these members without the need for disambiguation in the class itself. By implementing an interface member explicitly, you can hide it from the class's public API. Instead, the member is accessed through a reference of the interface type. This means that while the class can implement the functionality required by the interface, the overlap in member names does not clutter the public interface of the class. For example, if two interfaces have a method called `Display()`, a class can implement both methods explicitly by prefixing them with the interface name. This avoids confusion for developers using the class, as only the intended interface's member will be accessible through its respective interface reference. The options discussing simplification of inheritance, exposing all members publicly, or enforcing contracts refer to different aspects of interface and class design but do not directly relate to the specific issue that explicit interface implementations address.