To test reference type variables for Nothing values, use the Is operator or the IsNot operator. : ByRef « Language Basics « VB.Net

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VB.Net » Language Basics » ByRef Screenshots  To test reference type variables for Nothing values, use the Is operator or the IsNot operator.    Module Module1     Sub Main()         Dim testObject As Object         testObject = Nothing         Console.WriteLine(testObject Is Nothing)         Dim tc As New TestClass         tc = Nothing         Console.WriteLine(tc IsNot Nothing)     End Sub     Class TestClass         Public field1 As Integer         Dim field2 As Boolean     End Class End Module             Related examples in the same category 1. Pass parameter By value or By Reference 2. Object parameter passed by Value and by Reference 3. Structure parameter passed by Value and by Reference 4. String parameter passed by Value and by Reference 5. Array parameter passed by Value and by Reference 6. Modify Array Element By Reference 7. Array passed By Reference