what is OverLoading and OverRiding in VB.NET

[Bali]

Hi,

I am newbie to VB.NET.
Kindly explain me what is overloading and overriding
in vb.net.How this can be achieved.
Please explain with some good examples.
So I will have a clear idea.


Thanks and regards
bali

[Edneeis]

Overloading is basically when you have more than one method with the same name but a different number of or different types of parameters. The application then determines which one to call based on the parameters used. Showing the 'Overloads' keyword is optional as long as all of the methods either use it or don't use it.

'will work
Public Sub Testing()
'code here
End Sub
 
Public Sub Testing(ByVal Filename As String)
'code here
End Sub
 
'this will also work
Public Overloads Sub Testing()
'code here
End Sub
 
Public Overloads Sub Testing(ByVal Filename As String)
'code here
End Sub
 
'but this will not because only one method uses the Overloads keyword
Public Sub Testing()
'code here
End Sub
 
Public [b]Overloads[/b] Sub Testing(ByVal Filename As String)
'code here
End Sub

Overrides is used by derived classes (classes that inherit from a base class) to replace the original method from the base class with one of its own, which must match the same method signature.

'base class
Public Class BaseClass
 
Public Overridable Sub Testing()
   Msgbox("Shown from the Base")
End Sub
 
End Class
 
'derived class
Public Class DerivedClass
   Inherits BaseClass
 
Public Overrides Sub Testing()
   Msgbox("Shown from the Derived")
End Sub
 
End Class
 
'then in an app
Dim bc as New BaseClass()
bc.Testing()
Dim dc as New DerivedClass()
dc.Testing()

[venerable bede]

I just thought I would let you know Edneeis....

Your knowledge of this subject scares me at times.

P.S
Dont work to hard