Question

I am converting some VB.NET code to C#, as I am more comfortable with it and it helps me in resolving issues faster. However, I came across this code which is NOT an error in VB.NET — but converting it to C# is generating a compiler error.

VB.NET Code

Select Case name
    Case "FSTF"
    .....
    Case "FSTF"
    .....
End Select

C# Converted Code

switch(name) {
    case "FSTF":
        ....;
        break;
    case "FSTF":
        ....;
        break;
}

And the error is:

The Label ‘case “FSTF”:’ already occurs in this switch statement.

What is the solution here — does it mean that in the VB.NET code, the second case statement was just a dummy — or was the first case a dummy?

Answer 1

From the documentation for Select…Case:

If testexpression matches an expressionlist clause in more than one Case clause, only the statements following the first match run.

So here the second case is effectively redundant. Personally I prefer the C# approach of highlighting what was almost certainly an unnoticed programming error rather than the deliberate introduction of a duplicate case…