The debate whether to use C# or Visual Basic .NET is not uncommon for most .NET developers. Certainly, one has a distinct preference, but the general idea is that you can do in C# what you can do in VB and vice versa, because the .NET Framework is our common denominator. No, I don’t mean XML literals versus automatic properties. It’s the end result that counts.
So I’m currently involved in some VB programming when we stumbled upon something peculiar. Here’s a simplified form of what my predecessor, also preferring C#, tried to do:
Public Class PropertyClass
Private m_name As String = String.Empty
Public Property Name() As String
Get
If m_name = String.Empty Then
Name = “Unknown”
End If
Return m_name
End Get
Set(ByVal value As String)
m_name = value
End Set
End Property
End Class
Simple enough, and here’s the C# version:
class PropertyClass
{
private string m_name = string.Empty;
public string Name
{
get
{
if (m_name == string.Empty) Name = “Unknown”;
return m_name;
}
set { m_name = value; }
}
}
What do you expect to happen here, using the C# version?
PropertyClass pc = new PropertyClass();
Console.WriteLine(pc.Name);
The output would show Unknown and that’s expected, right?
And what would it be using the VB version?
Dim pc As New PropertyClass
Console.Write(pc.Name)
Well, surpsingly, at least to me, the output is… nothing! Yes, you try it. If we look at the compiler output. Here’s what the C# compiler made of it:
…
L_0016: brtrue.s L_0024
L_0018: ldarg.0
L_0019: ldstr “Unknown”
L_001e: call instance void CSharpProperty.PropertyClass::set_Name(string)
L_0023: nop
L_0024: ldarg.0
…
I’m no expert in reading IL, but clearly you see a call to the set_Name method. For VB, the compiler turns it into:
L_0015: stloc.1
L_0016: ldloc.1
L_0017: brfalse.s L_001f
L_0019: ldstr “Unknown”
L_001e: stloc.0
L_001f: nop
L_0020: ldarg.0
It’s completely gone. The compiler simply removed the
Name = “Unknown”
It appears there’s more difference between VB.NET and C# than I thought. I certainly hope to return to some C# code soon.