How to Type Cast null as Bool in C#?

Question

I'm having one null-able bool (bool?) variable, it holds a value null. One more variable of type pure bool, I tried to convert the null-able bool to bool. But I faced an error "Nullable object must have a value."

My C# Code is

bool? x = (bool?) null;
bool y = (bool)x;

Your value is `null`...it has no `bool` value to be cast to - if you'd like the default value for the type to be assigned if `x` is null, use the `GetValueOrDefault()` method. — Preston Guillot, Jan 04 '16 at 05:51

score 40 · Accepted Answer · answered Jan 04 '16 at 05:50

40

Use x.GetValueOrDefault() to assign default value (false for System.Boolean) to y in the event that x.HasValue == false.

Alternatively you can use the null-coalescing operator (??), like so:

bool y = x ?? false;

answered Jan 04 '16 at 05:50

Kirill Shlenskiy

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I'd use the alternative one primarily .. :) – Ken Kin Mar 08 '19 at 18:49

score 0 · Answer 2 · answered Jan 06 '22 at 10:55

0

Checking for equality with a boolean constant is a convenient shortcut:

        var x = (bool?) null;
        var y = x == true;

answered Jan 06 '22 at 10:55

pasx

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score -1 · Answer 3 · edited Jan 04 '16 at 06:00

-1

If I have a property boolean

If (HasData.HasValue) Then
            Dim value As Boolean = HasData.Value
        End If
        ' or you can also do this
        If (HasData IsNot Nothing) Then

    End If

That should fix your bug.

hope this helps

edited Jan 04 '16 at 06:00

Ghasem

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answered Jan 04 '16 at 05:58

Mangukiya Hardik

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How to Type Cast null as Bool in C#?

3 Answers3