Question

This is a general question about Object Orientation and specifically overloading functions in .NET (or any other framework or language). I am looking at an application that has a lot of duplicate code. For example, have a look at the following functions:

Public Function Test(ByVal Test1 As String)

//code that is specifically relevant to Test1 variable

End Function

Public Function Test (ByVal Test1 As String, ByVal Test2 As String)
    //code that is specifically relevant to Test1 variable
    //code that is specifically relevant to Test2 variable
End Function

I would of thought that best pratice would be to put: //code that is specifically relevant to Test1 variable in a separate function as it is common in both functions. Is this the case? I have always thought that duplicate code is a very bad idea.

Answer 1

It is not better:

Public Function Test(ByVal Test1 As String) 
    //code that is specifically relevant to Test1 variable
End Function 

Public Function Test (ByVal Test1 As String, ByVal Test2 As String) 
    Test(Test1)
    //code that is specifically relevant to Test2 variable 
End Function 

Overloading ideally should be about adding aditional features to the original function but preserving it’s original behaviour in case you use it somewhere else in your code.