understanding Null Zero

[Tuckejam]

Need some help understanding the Null Zero please

I think I understand that it turns a null variant to a zero value, but I don't understand where the need to do that comes from. (and I don't really know what a variant is)

in the code below we are using a button to open a form and send information about the record selected to the form we are opening
(selecting a customer record and clicking the edit customer button to open the edit customer form with that selected customers information)

so, do forms, by default, open with a null (argument? .... value? ... ) and by turning the null into a zero we are just kicking that out of the way so we can do other stuff
if that's whats happening why do forms default by opening with null

and on a much deeper level what is the difference between Null and Zero

Private Sub Form_Open(Cancel As Integer)
Me.AllowAdditions = False
Me.AllowEdits = False
Me.AllowDeletions = False
If Nz(Me.OpenArgs) <> 0 Then
Me!CustID.SetFocus
DoCmd.FindRecord Me.OpenArgs
Else
Me.OrderBy = "CustID"
Me.OrderByOn = True
End If


End Sub

Thanks for the help, it is always greatly appreciated.

[moke123]

heres a pretty good article on nulls

https://www.utteraccess.com/wiki/Nul...Their_Behavior

Heres a reference for NZ()
https://www.techonthenet.com/access/...dvanced/nz.php

in the code below we are using a button to open a form and send information about the record selected to the form we are opening
(selecting a customer record and clicking the edit customer button to open the edit customer form with that selected customers information)

To open a form to a specific record use the Docmd.OpenForm method with a where condition
https://docs.microsoft.com/en-us/off...docmd.openform