Polymorphism:- Polymorphism is one of
the crucial features of VB.NET, It means "The ability to take on different form", It is also called as Overloading which means the use of same thing for
different purposes. Using Polymorphism we can create as many functions we want
with one function name but with different argument list. The function performs
different operations based on the argument list in the function call. The exact
function to be invoked will be determined by checking the type and number of
arguments in the function.
Definition:- "Manipulated the object of
various classes and invoke method on one object without knowing the object
type".
Example:-polymorphism real word examples
are Student, Manager, Animal and etc.
Polymorphism can be divide in to two parts, that are given bellow
- Compile time polymorphism
- Run time polymorphism
Compile time polymorphism:- compile time
polymorphism achieved by "Method Overloading", means that same name function
with deferent parameters in same class called compile time polymorphism.
Module Module1
Sub Main()
Dim two As New One()
WriteLine(two.add(10))
'calls the function with one argument
WriteLine(two.add(10, 20))
'calls the function with two arguments
WriteLine(two.add(10, 20, 30))
'calls the function with three arguments
End Sub
End Module
Public Class One
Public i, j, k As Integer
Public Function add(ByVal
i As Integer) As Integer
'function with one argument
Return i
End Function
Public Function add(ByVal
i As Integer, ByVal j
As Integer) As Integer
'function with two arguments
Return i + j
End Function
Public Function add(ByVal
i As Integer, ByVal j
As Integer, ByVal k
As Integer) As Integer
'function with three arguments
Return i + j + k
End Function
End Class
Output:10
20
30
Run time Polymorphism:-Run time
polymorphism achieved by "Method Overriding or Operator Overloading", means that
same name function with
same parameters in deferent deferent classes called Run time Polymorphism .
Public Class poly
Public Sub show()
WriteLine("hellow")
End Sub
End Class
Public Class poly2
Inherits poly
Public Sub show()
WriteLine("world")
End Sub
End Class
Class output
Public Shared Sub Main()
Dim a As poly2 =
New poly2()
a.show()
End Sub
End Class
Output: World