[AccessD] Change in the evaluation of IIF, or something else?

Here is my imagined picture of this - and I may very well have it wrong.

Not just not in Access VBA, but also with Excel VBA I have seen Cell -
which normally has .Value2 as its default property (or maybe .Value) get
instead handled as an object when adding to a collection or other
situations.


On Thu, Feb 5, 2015 at 7:43 AM, Andy Lacey <andy at minstersystems.co.uk>
wrote:

> Gustav, you are, as ever, correct.
>
> It was always my belief that .Value is the default if no property
> specified, and
> that belief seems to hold good everywhere else. Why not here?
>
> Andy
>
>
>
>
> > On 05 February 2015 at 12:25 Gustav Brock <gustav at cactus.dk> wrote:
> >
> >
> > Hi Andy
> >
> > It probably tries to pull the object.
> > Use the Value property:
> >
> > res = Weekday(rst!fld.Value, vbUseSystemDayOfWeek)
> >
> > /gustav
> >
> > -----Oprindelig meddelelse-----
> > Fra: accessd-bounces at databaseadvisors.com
> > [mailto:accessd-bounces at databaseadvisors.com] På vegne af Andy Lacey
> > Sendt: 5. februar 2015 13:13
> > Til: Access Developers discussion and problem solving
> > Emne: Re: [AccessD] Change in the evaluation of IIF, or something else?
> >
> > Well there's a thing.
> >
> > Weekday(Null) returns Null
> >
> > Weekday(var) where var is Null returns Null
> >
> > Weekday(rst!fld) where rst!fld is Null gives Invalid Use Of Null
> >
> > ????????
> >
> > Andy
> >
> >
> > > On 05 February 2015 at 11:33 Gustav Brock <gustav at cactus.dk> wrote:
> > >
> > >
> > > Hi Andy
> > >
> > > How about:
> > >
> > > res = Weekday(var)
> > >
> > > or rather:
> > >
> > > res = Weekday(var, vbUseSystemDayOfWeek)
> > >
> > > Works in A2013.
> > >
> > > /gustav
> > >
> > > -----Oprindelig meddelelse-----
> > > Fra: accessd-bounces at databaseadvisors.com
> > > [mailto:accessd-bounces at databaseadvisors.com] På vegne af Andy Lacey
> > > Sendt: 5. februar 2015 12:08
> > > Til: Access Developers discussion and problem solving
> > > Emne: [AccessD] Change in the evaluation of IIF, or something else?
> > >
> > > Hi folks
> > >
> > > I'm moving an ancient and very big db from A97 to A2010. I've just
> > > been tripped up by a difference in behaviour when using IIF. Here's
> > > the line of
> > > code:
> > >
> > > res=IIF(IsNull(var),Null,Weekday(var))
> > >
> > > In A97 this works fine and gives me Null. However, in A2010 this is
> > > crashing with Invalid Use of Null. It must evaluate both true and
> > > false element(s) of the IIF regardless. (Queries do not appear to do
> this,
> > > they work as before).
> > >
> > > Is this a general rule in A2010. Is there anything I can do to change
> > > this behaviour? I know I can code round it in a number of ways but
> > > finding all instances of this in a humungous db is a horrendous
> > > prospect. I'm praying for a magic answer.
> > >
> > > Hang on, read on.
> > >
> > > After a bit more digging I'm not sure now where this will and will not
> > > arise.
> > > I just tried the following:
> > >
> > > res=iif(isnull(var),null,instr(var,"12345","1"))
> > >
> > > and, unlike the Weekday function, that crashes in A97 which blows out
> > > of the water the idea that the False part of the IIF function wasn't
> > > evaluated before.
> > > So now I'm not sure if there is a rule by which all functions abide.
> > >
> > > Confused.
> > >
> > > Oh and pleeease don't tell me that I shouldn't have coded like that in
> > > the first place. That wouldn't be helpful.
> > >
> > > Andy
> >
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