[RESOLVED] [2005] Null In array

[shakti5385]

Hi all
How to check Null value in the array
See this

Dim FileName() As String = Nothing
            If Not IsDBNull(DataTable.Rows(0).Item("Document")) Then FileName = Split(DataTable.Rows(0).Item("Document"), ",")
            For Index As Integer = 0 To UBound(FileName)
                Me.lstFiles.Items.Add(Application.StartupPath & "\ShaktiProjectAttachDocument\" & FileName(Index))
            Next

if this is IsDBNull(DataTable.Rows(0).Item("Document")) Nothing then then there is Null in the array and the error will occuring here.For Index As Integer = 0 To UBound(FileName)
so How to avoid this error.

[superbovine]

change your NULL to nothing.

[Kimmy4]

Couldn't you just replace any element that is NULL with an empty string?

[jmcilhinney]

How about you put the For loop inside the If block too? Also, you don't need that array variable at all:

If Not DataTable.Rows(0).IsNull("Document") Then
    Dim path As String = IO.Path.Combine(Application.StartupPath, "ShaktiProjectAttachDocument")
 
    Me.lstFiles.BeginUpdate()
 
    For Each fileName As String In CStr(DataTable.Rows(0)("Document")).Split(","c)
        Me.lstFiles.Items.Add(IO.Path.Combine(path, fileName)
    Next fileName
 
    Me.lstFiles.EndUpdate()
End If

Now, I'm afraid I can't help but say this. I'm a big fan of consistency in code and I'm also not a big fan of Hungarian notation. You've got a variable named "lstFiles", so you're using Hungarian notation. I'd suggest not doing that, but if you're going to then may I suggest that you at least be consistent? You've also got a variables named "FileName", "DataTable" and "Index". If you're not going to use Hungarian everywhere then what's the point of using it at all?

[shakti5385]

:[End If[/Highlight]Now, I'm afraid I can't help but say this. I'm a big fan of consistency in code and I'm also not a big fan of Hungarian notation. You've got a variable named "lstFiles", so you're using Hungarian notation. I'd suggest not doing that, but if you're going to then may I suggest that you at least be consistent? You've also got a variables named "FileName", "DataTable" and "Index". If you're not going to use Hungarian everywhere then what's the point of using it at all?

That's nice sir but can you please tell me what is mistake and how to correct it??
I can not understand above line.
thanks

[jmcilhinney]

In short, use Hungarian notation all the time or not at all. If you aren't going to use prefixes to identify the type of every variable then don't use them on any variable.

[shakti5385]

Please provide some example of the Hungarian notation
Thanks

[danasegarane]

What about this one

If FileName.Length() > 0 Then
            For Index As Integer = 0 To UBound(FileName)
                If FileName(Index).ToString().Length > 0 Then
                    Me.lstFiles.Items.Add(Application.StartupPath & "\ShaktiProjectAttachDocument\" & FileName(Index))
                End If
            Next
        End If

[jmcilhinney]

Please provide some example of the Hungarian notation

I already did.

You've got a variable named "lstFiles", so you're using Hungarian notation.

If you aren't going to use prefixes to identify the type of every variable then don't use them on any variable.

I do feel like I'm speaking Swahili some times. The fact that you don't know what it is is a prime indication that you're one of the many people who use it because they've seen it somewhere without any thought for its purpose. The fact that you don't use it consistently is a prime indication that you don't feel that its intended purpose is worth fulfilling. If that's the case, don't use it at all.

[shakti5385]

Thanks sir for reply
then what i use at the place of the lstFiles",
lstFiles", is the listbox

[jmcilhinney]

If it's a list of files then "fileList" would be a logical choice don't you think?

[shakti5385]

If it's a list of files then "fileList" would be a logical choice don't you think?

Thanks JMC for guidance