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Asked: 2026-05-10T23:19:09+00:00

I normally use C# and I’m attempting to convert a qbasic programmer to the

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I normally use C# and I’m attempting to convert a qbasic programmer to the joys of object oriented programming by easing him into VB 2005.

Below is a extremely simplified version of what I’m trying to accomplish. It successfully compiles, but all members in the array of card objects are set to ‘Nothing’. The test line throws a NullReferenceException. What am I doing wrong? 

    Sub Main()         Dim deck1 As New Deck         Console.WriteLine('Test: ' & deck1.cards(2).face)     End Sub      Class Card         Public face As String         Sub New()             face = 'Blank'         End Sub     End Class      Class Deck         Public cards(51) As Card     End Class
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  1. Yes, when you create an array in .NET, every element of the array is set to the default value of the element type – which is null/Nothing for classes.

    You need to populate the array before you use it (or expect it to be full of null references).

    Note that this would have behaved exactly the same way in C#.

    EDIT: As no-one’s actually posted population code that would work yet, here it is:

    Class Deck     Public cards(51) As Card      Public Sub New()         For i As Integer = 0 To cards.Length-1             cards(i) = New Card()         Next     End Sub End Class
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