Passing null or Optional values to functions in VB6

Posted on 2005-03-28
Medium Priority
Last Modified: 2008-03-03
I have written a DLL function that takes 11 parameters, However all eleven parameters may not allways be needed.
How can I call my function in a way that I dont have to specify emtpy strings. ie like this:

     X = myFunction(Val1, Val2, Val3, , , , , , , Val10, Val11)

Currently I have to do this :

     X = myFunction(Val1, Val2, Val3, "", "", 0, 0, "", 0, Val10, Val11)

MSDN says:
An argument can only be omitted from a call to a user-defined procedure if it was declared Optional in the procedure declaration. Either supply the argument in the call or declare the parameter Optional in the definition.

I have tried:
Optional Val1 As String
Val1 As Optional String
Val1 As String Optional, etc

Please advise,
Question by:gjok
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LVL 27

Accepted Solution

Dabas earned 500 total points
ID: 13642621

True, you can declare a parameter as optional, but once you have done so, all parameters AFTER that one must also be declared optional. If you want ALL parameters to be optional then your declarion should be:

Public Function myFunction(Optinal Val1 as String, Optional Val2 as String, Optional Val3 as String.... Optional Val11 as String) as Whatever


Author Comment

ID: 13642641
Many thanks, that works great!

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