Implementation of multiple interfaces in VB.NET


In this articals we will see how to implement of multiple interface in an interface can obtain one or more methods,properties,indexers and events.
But none of them are implemented in the interface is the responsibility of the class that  implements the interface to define the code for implementation of these does not support directly multiple inheritance but using interface we can use multiple inheritance.
interface keywords to create an interface& implement keywords is use to implememt the interface.
this code implementing two interfaces.The class Computation implement two interfaces Addition and declare two data members and define the code for the methods Add and multiplication.

code implementation of Multiple interfaces:

Module Module1

    Interface Addition

        Function Add() As Integer

    End Interface

    Interface Multiplication

        Function Mul() As Integer

    End Interface

    Class Computation

        Inherits Addition

        Inherits Multiplication

        Private x As Integer, y As Integer

        Public Sub New(ByVal x As Integer, ByVal y As Integer)

            Me.x = x

            Me.y = y

        End Sub

        Public Function Add() As Integer

            Return (x + y)

        End Function

        Public Function Mul() As Integer

            Return (x * y)

        End Function

    End Class

    Class interfaceTest1

        Sub Main()

            Dim com As New Computation(10, 20)

            Dim add As Addition = DirectCast(com, Addition)

            Console.WriteLine("sum =" & add.Add())

            Dim mul As Multiplication = DirectCast(com, Multiplication)

            Console.WriteLine("product =+" & mul.Mul())

        End Sub

    End Class

 End Module

 Ouput of program will be: