Question

This is ok in C#:

private int total;
public int Total {
    get {
        return total;
    }
}

So the backing field total is spelled the same as the Property Total with the only thing telling them apart being the case of the T.

With VB.NET VS complains if I try to do the following. In fact it won’t even let me write Return total with a lower case t and auto-corrects to an upper case T

But if I spell the backing field differently then it seems to be ok:

Private fTotal As Integer
Public ReadOnly Property Total() As Integer
    Get
        Return fTotal
    End Get
End Property

I realize they are different languages but is there a logical reason behind this difference? (EDIT originally said “apparent inconsistency” rather than “difference”)

Also – I assume even though Visual Studio auto-corrects the case of my VB.NET but in reality this language is not case-sensitive?

Answer 1

I realize they are different languages but is there a logical reason behind this apparent inconsistency?

The original reason is simply historical: VB is based on BASIC which, like other languages at the time (FORTRAN) was case insensitive (but was usually written in all-uppercase).

Furthermore, I don’t see any inconsistency: inside VB, the casing is entirely consistent. In particular, it’s not “sort of case-sensitive” as your title asks.

There is a logical reason to be case insensitive, even today: it makes it harder to introduce bugs due to name clashes; consider the following C# code:

private int total;

public int Total {
    get { return total; }
    set { Total = value; }
}

Did you spot the error immediately? If so, not bad (the syntax highlight here helps). In VB, this class of errors cannot happen. But in practice I think this class of bugs isn’t all that problematic because once identified they are easily eliminated. So while this is a reason for case insensitivity, it’s not a very strong one.

Finally, notice that Windows and OS X file systems use the same convention as VB here: the file system is case insensitive (filename case doesn’t matter) but case aware – meaning the file system preserves the original casing of a filename and displays it correctly but when comparing, it doesn’t consider case.