Passing Null As Parameter

[homer2002]

Still having Null trouble

Can anyone get this to work.
I'm having a stupid day
(obviously i will be passing variables into the function in reality)
________________________________

Function testnull(sString As String) As String
If IsNull(sString) Then sString = ""
testnull = sstring
End Function


Private Sub Command0_Click()
msgbox testnull(Null)
End Sub

_____________________________


Access wont allow me to pass Null into the function.

cheers Homer

 

[Mile-O]

Why are you trying to pass a Null value?

 

[homer2002]

I'm not trying to pass a null value

i'm trying to stop a function crashing when I try to pass in
a string that may or may not contain a null value.

 

[Mile-O]

Wrong order, then.

You should check if the string is Null before you send it.

 

[Mile-O]

Also, rather than use "" for assigning a null string you'd be better to use the Access constant provided: vbNullString.

 

[homer2002]

Oh right I gotya.


I thought i would be able to handle it within the function.

cheers

 

[Mile-O]

I thought i would be able to handle it within the function.

No, because the String parameter expects a string value. The error is triggered when you try to send the Null data to a string data type.

 

[Pat Hartman]

I guess what is confusing people is why you are writing your own function to change nulls to zero-length strings. There is a VBA function that will change nulls to whatever value you choose. Nz(YourNumericField, 0) or Nz(YourTextField, "N/A") You can use whatever you want as the second argument provided it is compatable with the field type.