C# v/s VB.NET

planoie · December 21st, 2004, 04:57 PM

C# would certainly be easier if you are coming from a C++ background. No question there.

Regarding operator overloading, this is a language capabilities issue and really not a language readability issue.

Regarding explicit interface implementation, I'm not sure why you beleive that you can't explicitly implement an interface in VB.NET. I have done it on many occasions.

planoie · December 21st, 2004, 05:23 PM

Quote:

quote:Originally posted by Hal Levy
There are so many things I see as "backward" in c#- like the dimensioning of variables...

I was going to keep my trap shut about more detailed aspect of my personal opinion of readability, but since you brought it up...

Yes, it is by far much easier to pick out a series (or a single) Dim statement than the non-VB method. Particularly when you're in an IDE that has code coloring or you work with people who make a habit of plopping initialization statements in any old place (no offense if you are one of those).

mehdi62b · December 22nd, 2004, 03:44 PM

Quote:

quote:Originally posted by planoie
Regarding explicit interface implementation, I'm not sure why you beleive that you can't explicitly implement an interface in VB.NET. I have done it on many occasions.

How do you implement this code in VB.NET?

Code:

interface IMyItf
{
     int Func(int i,int j);
}
public class Derived:IMyItf 
{
 public int Func(int i,int j) 
 {
  return 100;
 }
 int IMyItf.Func(int i,int j)
 {
  return 1000;
 }
}

_____________________________
Mehdi.
software engineering student.
Looking for a good job for summer 2005.

mmrzadeh · December 23rd, 2004, 01:37 AM

Quote:

quote:How do you implement this code in VB.NET?

Code:

interface IMyItf
{
     int Func(int i,int j);
}
public class Derived:IMyItf 
{
 public int Func(int i,int j) 
 {
  return 100;
 }
 int IMyItf.Func(int i,int j)
 {
  return 1000;
 }
}

i implement it in vb this way:

in IMyItf.cls i write:

Code:

public fuction func(i as int,j as int)as int
end function

in Derived.cls i write:

Code:

implements IMyItf

private function IMyItf_func(i as int,j as int)as int
IMyItf_func=1000
end function

public function func(i as int,j az int)az int
func=100
end function

i dont know about vb.net!

planoie · December 28th, 2004, 04:20 PM

mehdi,

I see what you are driving at with this. Here is how I would implement it, pretty much the same as mmrzadeh:

Interface IMyItf
     Function Func(i As Integer, j As Integer) As Integer
End Interface

Public Class Derived
    Implements IMyItf
    Public Func(i As Integer, j As Integer) As Integer
        Return 100
    End Function
    Public IMyItf_Func(i As Integer, j As Integer) As Integer Implements IMyItf.Func
        Return 1000
    End Function
End Class

HOWEVER: I would never write a class that had two different methods with the same name. That's one of the things I like about the way you implement interfaces in VB. You don't have to have methods that match the interface name. Admittedly, you usually would implement the method with the same name.

IMO, the example you posted is a poor design (despite it's intension as an example). Is this an example they have given you at school?

mehdi62b · December 29th, 2004, 10:36 AM

Peter,I mistook in my previous post I didnt mean that code,please see below code,

Code:

interface IMyItf
{
     int Func(int i,int j);
}
public class Base1:IMyItf
{
 int IMyItf.Func(int i,int j)//a private member
 {
  return 100;
 }
}
//reimplementing the IMyItf in Derived class
public class Derived:Base1,IMyItf 
{
 public int Func(int i,int j) 
 {
  return 1000;
 }
}

as you see in above code if Derived class wants to use IMyItf it should implement the IMyItf,but this ability is just available in C#,you know mainly VB.NET doesnt let us reimplement interfaces in subclasses,maybe you notice me why your example implements the interface in Base class explicitly,the answer is sometimes maybe we want to use some classes in .NET framework and we should extend them,but some interfaces have been implemented explicitly(private) so we have to implement them in Derived class,but as I mentioned VB.NET compiler throws an error:
Interface 'IMyItf' is already implemented by base class 'Base1'.
(for example take a look at this link,http://weblogs.asp.net/fbouma/archiv.../12/37199.aspx)
it seems this ability comes to VB.NET in Whidbey.

Quote:

quote:Is this an example they have given you at school?

no,it wasnt.

_____________________________
Mehdi.
software engineering student.
Looking for a good job for summer 2005.

mmrzadeh · December 29th, 2004, 10:44 PM

Quote:

quote:

Quote:

you know mainly VB.NET doesnt let us reimplement interfaces in subclasses

Please excuse me mehdi,are you sure about it?
I can simply reimplement interfaces in subclasses in vb .
I think ,it hasnt problem in vb.net

mehdi62b · December 30th, 2004, 10:03 AM

I think it has some problem in VB.NET,see below code,

Code:

//C# Syntax
interface IMyItf
{
     int Func(int i,int j);
}
public class Base1:IMyItf
{
 int IMyItf.Func(int i,int j)
 {
  return 100;
 }
}
//Reimplementing the IMyItf in Derived class permited
public class Derived:Base1,IMyItf 
{
 public int Func(int i,int j) 
 {
  return 1000;
 }
}
'VB.NET Syntax
Public Interface IMyItf
    Function Func(ByVal i As Integer, ByVal j As Integer) As Integer
End Interface
Public Class Base1
    Implements IMyItf
    Private Function IMyItf_Func(ByVal i As Integer, ByVal j As Integer) As Integer Implements IMyItf.Func
        Return 100
    End Function
End Class
'Reimplementing the IMyItf in Derived class not permited
Public Class Derived : Inherits Base1
    Implements IMyItf
    Public Function Func(ByVal i As Integer, ByVal j As Integer) As Integer
        Return 1000
    End Function
End Class

VB.NET compiler throws:
Interface 'IMyItf' is already implemented by base class 'Base1'.

_____________________________
Mehdi.
software engineering student.
Looking for a good job for summer 2005.

mmrzadeh · December 31st, 2004, 10:00 PM

mehdi,
Thank you for your practical example.It clearly show that

Quote:

quote:
C# is more ... and represents OOP concepts better...

however i believed before, but you surprised me!

planoie · January 5th, 2005, 12:48 PM

Mehdi,

I think I see what you are driving at here. What you are showing is:
1) We have interface 'IMyItf' (with 'int Func(int i,int j)')
2) Class 'Base1' implements 'IMyItf.Func()'
3) 'Derived' inherits from Base1
4) 'Derived' reimplements the method 'Func()'.

Is the intent of 'Derived.Func' to override 'Base1.Func'? In VB, this can be achieved with the 'Overrides' keyword. In C#, the same can be achieved by implementing the same interface on the derived class and reimplementing the interface method.

Here's what I tried in VB:

Imports System

Public Interface IMyItf
    Sub MyMethod()
End Interface
Public Class Base1
    Implements IMyItf
    Public Overridable Sub MyMethod() Implements IMyItf.MyMethod
        Console.WriteLine("Base1.MyMethod")
    End Sub
End Class
Public Class Derived : Inherits Base1
    Public Overrides Sub MyMethod()
        Console.WriteLine("Derived.MyMethod")
    End Sub
End Class
Module Module1
    Public Sub Main()
        Dim iTest As IMyItf
        iTest = New Base1
        iTest.MyMethod()
        iTest = New Derived
        iTest.MyMethod()
    End Sub
End Module

And translated into C#:

using System;

namespace MyInterfaceTest{
    public interface IMyItf{
        void MyMethod();
    }
    public class Base1 : IMyItf{
        void IMyItf.MyMethod(){
            Console.WriteLine("Base1.MyMethod");
        }
    }
    public class Derived : Base1, IMyItf{
        void IMyItf.MyMethod(){ //
            Console.WriteLine("Derived.MyMethod");
        }
    }
    class Module1{
        public static void Main(){
            IMyItf iTest;
            iTest = new Base1();
            iTest.MyMethod();
            iTest = new Derived();
            iTest.MyMethod();
        }
    }
}

The output of each of these is:

Base1.MyMethod
Derived.MyMethod