VB.NET Nothing evaluating to False

Question

Consider the following VB.NET code:

Sub ObjectTest()
    Dim active As Object = Nothing

    If active = False Then
        Console.WriteLine("false")
    End If

    If active = True Then
        Console.WriteLine("true")
    End If

    If active = Nothing Then
        Console.WriteLine("nothing")
    End If
End Sub

the output I get on the console is

false
nothing

This means

If active = False

is succeeding. How can this be? active is set to nothing so how can it be false? It is not false, it is nothing. We know this because the

If active = Nothing

condition succeeds.

Incidentally, if I change the code to:

Sub ObjectTest()
    Dim active As Object = vbnull

    If active = False Then
        Console.WriteLine("false")
    End If

    If active = True Then
        Console.WriteLine("true")
    End If

    If active = vbnull Then
        Console.WriteLine("null")
    End If
End Sub

The only output I get is "null" Clearly in VB.NET then, "nothing" does not mean "null"

What is causing the condition to think active is equal to false?

Set `Option Strict` to ON. Then you can't switch types as you wish. — Tim Schmelter, Oct 04 '17 at 14:10
Apologies for the duplicate. The link you have posted makes perfect sense — SE1986, Oct 04 '17 at 14:13
In my code I used object because the result I am looking for is a boolean that could be null. The way round the issue above is to decalre Dim active as boolean? — SE1986, Oct 04 '17 at 14:16
"Dim active as boolean?" is a Boolean that can be null. Also, you should use IS and not = when comparing with Nothing — the_lotus, Oct 04 '17 at 14:27

VB.NET Nothing evaluating to False

0 Answers0