Explicit Interface Implementation

We know that a class can implement more than one interface, now what if a class implements 2 interfaces and if both the interfaces contain a method with the same name and signature, how do we implement these methods in the class body. This is where explicit Interface comes into play. In such cases the method name should be prefixed with the interface name and a (.) symbol.

The following example contains 2 interfaces IEmployee and IDepartment, both the interfaces contain a method GetName() with the same name and signature. The class OfficeClass implements both the interfaces and implements the GetName method from both the interfaces using Explicit Interface Implementation.

    interface IEmployee

    {

        string GetName();

    }

    //

    interface IDepartment

    {

        string GetName();

    }

    //

    class OfficeClass : IEmployee, IDepartment

    {

        string IEmployee.GetName()

        {

            return "test employee";

        }

        //

        string IDepartment.GetName()

        {

            return "test department";

        }

    }

Though both the interfaces have methods with the same name and signature, it is mandatory to implement methods from both the interfaces failing which will lead to a compiler error as follows.

interface IEmployee

    {

        string GetName();

    }

    //

    interface IDepartment

    {

        string GetName();

    }

    //

    class OfficeClass : IEmployee, IDepartment

    {

        string IEmployee.GetName()

        {

            return "test employee";

        }

    }

Error:
OfficeClass does not implement interface member IDepartment.GetName()