Microsoft Certified Solutions Developer (MCSD) Certification Practice Test

What does explicit interface implementation achieve?

1. Allows a class to expose all its members

2. Hides members of a class from outside access

3. Increases method execution speed

4. Enables multiple inheritance

The correct answer is: Hides members of a class from outside access

Explicit interface implementation is a technique used in object-oriented programming, particularly in languages like C#. It allows a class to implement members of an interface in a way that they are only accessible through the interface, not through the class itself. This means that the members can effectively be "hidden" from the outside world when viewed through the class, promoting encapsulation. By using explicit interface implementation, developers can control how interface methods are accessed. This is particularly useful when a class implements multiple interfaces that may contain members with the same signature. In such cases, explicit implementation allows the class to provide distinct implementations for each interface without exposing those methods through the class's public member list. For instance, if a class implements an interface, the methods defined in the interface can be implemented explicitly so that they can only be called when the class instance is referenced as the interface type. This helps avoid potential conflicts and keeps the class interface clean, enhancing the overall design by enforcing separation of concerns. The other choices do not accurately reflect the purpose of explicit interface implementation. While a class's members can be hidden from outside access through encapsulation techniques, explicit interface implementation specifically pertains to interface members and offers finer control over their visibility and accessibility.