Blog

Method Overloading in VB.Net

Posted by Deepak Kumar Verma in Blogs | Visual Basic 2010 on Feb 17, 2011

A brief explanation about the Method Overloading in VB.Net & it's Implementation

Tweet
2169
0

METHOD OVERLOADING :
Method Overloading allows us to write different versions of a method (i.e. a single class can contain more than one methods (Sub / Functions) of same name but of different implementation). And compiler will automatically select the appropriate method based on parameters passed.
Consider following points in order to implement/understand method overloading :
All the overloaded methods must be of same procedure type (either only Sub or only Function).
Allowed :
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
Public Overloads Function add(ByVal a As Long, ByVal b As Long)
Not Allowed :
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
Public Overloads Sub add(ByVal a As Long, ByVal b As Long)
Don't repeat same parameters with same data types in parameter, it will show an error
Example :
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
Overloaded methods must have different number parameters and/or Different data types in the parameters
Different number of parameters
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer, ByVal c As Integer)
Different data type in parameters
Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
Public Overloads Function add(ByVal a As Long, ByVal b As Long)
Inherited Classes can also overload their own methods or their base class methods
Example 1 :
Imports System.Console
Module Module1
    Public Class demo
        Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
            WriteLine("You are in function add(integer, integer)")
            Return a + b
        End Function
        Public Overloads Function add(ByVal a As Long, ByVal b As Long)
            WriteLine("You are in function add(long, long)")
            Return a + b
        End Function
    End Class
    Sub Main()
        Dim obj As New demo
        WriteLine(obj.add(2147483640, 4))
        WriteLine(obj.add(2147483648, 1))
        WriteLine("press return to exit...")
        Read()
    End Sub
End Module
Output :

Example 2 :
Imports System.Console
Module Module1
    Public Class demo
        Public Overloads Function add(ByVal a As Integer, ByVal b As Integer)
            WriteLine("You are in function add(a,b)")
            Return a + b
        End Function
        Public Overloads Function add(ByVal a As Integer, ByVal b As Integer, ByVal c As Integer)
            WriteLine("You are in function add(a, b, c)")
            Return a + b + c
        End Function
    End Class
    Sub Main()
        Dim obj As New demo
        WriteLine(obj.add(4, 2))
        WriteLine(obj.add(4, 5, 1))
        WriteLine("press return to exit...")
        Read()
    End Sub
End Module
Output :

post comment