Question

I have a question about garbage collection when an object seemingly falls out of scope but may still stay alive as other classes are still holding references to it. Please look through the code below. Thanks.

Public Class MainForm

    Private Sub Work
         Dim Obj1 as New DataTable
         Dim Obj2 as New DataTable

         Helper.TestMethod1(Obj1)
         Helper.TestMethod2(Obj2)
    End Sub

End Class

Public Class Helper

     Private Shared Obj1Reference as Object

     Public Shared Sub TestMethod1 (ByVal obj1Ref as Object)
         Obj1Reference = obj1Ref
     End Sub

     Public Shared Sub TestMethod2 (ByVal obj2Ref as Object)
          'Do Something with obj2Ref
     End Sub

End Class

Would both Obj1 and Obj2 be put on the garbage collection queue after the Work method exits. From my understanding, Obj2 is put on the queue but not Obj1 as the static helper class is holding a reference to Obj1. Please correct me if I am wrong.

Answer 1

Nothing is collected because neither of your objects have been initialized and are therefore both Nothing. If they were initialized, then yes, one would continue to exist because it would continue to have a reference to it and the other would not because it would not have a reference to it.