Return Null Nothing for validation purpose

Let say I have the following simple code.
        Dim newStudent

        newStudent = Nothing

        If Not IsNothing(newStudent) Then
            Console.WriteLine("They is something")  <-- This is printed
        Else
            Console.WriteLine("They is nothing")
        End If

I need to do the above so let say when the user enter an invalid data, the fuction will return nothing so that I know the function has detected an error e.g. newStudent = GetStudentDetails() in user input and therefore return nothing so that my calling program will reject the entry.

But the above does not work, even when newStudent is nothing which indicate that they is nothing it still say they is something, help, any alternative method is welcome.
CplusPlusAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

appariCommented:

is this code is in VB.NET?
0
CplusPlusAuthor Commented:
To appari

Yes. sorry about forgetting,,,
0
appariCommented:
what's the datatype of newStudent?

i have tested with type string, seems to work fine

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim x As String
        x = Nothing
        If Not IsNothing(x) Then
            MsgBox("Not Nothing")
        Else
            MsgBox("Nothing")
        End If
        x = "qwqw#"
        If Not IsNothing(x) Then
            MsgBox("Not Nothing")
        Else
            MsgBox("Nothing")
        End If
    End Sub
0
Ultimate Tool Kit for Technology Solution Provider

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy now.

CplusPlusAuthor Commented:
its actually a struc as in Dim newStudent As Student
 
   Structure Student
        Public Name As String
        Public ID As String
        Public BirthYear As Integer
    End Structure
0
Ryan ChongCommented:
Try use the isdbnull function?

If IsDBNull(x) Then
       msgbox "is null"
   Else
       msgbox "not is null"
   End If
0
CplusPlusAuthor Commented:
does not work ryancys, but thanks anyway.
0
appariCommented:
you can try something like this

      Dim x As student
        x = Nothing
        If Not IsNothing(x.id) Then
            MsgBox("Not Nothing")
        Else
            MsgBox("Nothing")
        End If
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
CplusPlusAuthor Commented:
Thanks appari, but it seem odd you have to do that to make it work...
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Visual Basic Classic

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.