Question

I’m trying to compare two variables of type nullable(of boolean) in VB.NET 2010. One of the variables has a value False and the other is Nothing. Now I was expecting the following expression to evaluate to true, but this is not the case:

Dim var1 as nullable(of boolean) = False
Dim var2 as nullable(of boolean)
var2 = Nothing

If var1 <> var2 Then
 msgbox "they are different"
End If

Why don’t I see my MsgBox? How should I compare two nullables (of boolean)?

Answer 1

You can use Nullable.Equals:

Indicates whether two specified Nullable(Of T) objects are equal.

If Not Nullable.Equals(var1, var2) Then
    MsgBox("they are different")
End If