[ASP/VBscript] Strange handling of Or comparisons

[Marja Ribbers]

Suppose I have the following test in ASP/VBscript:

If (IsEmpty(l_sAppVar) Or l_sAppVar = "" Or DateDiff("d", CDate(l_sAppVar), Date()) > 0) Then
...
End If

then ASP complains about a type mismatch for CDate(l_sAppVar) when l_sAppVar is indeed "".

This seems strange to me, because when the first or second evaluation in the test returns True, then it is not necessary anymore to evaluate the other components of the test.
Am I missing something?

--
Marja Ribbers-de Vroed

Company website:
[url]www.webwaresystems.nl[/url]
Dreamweaver extensions:
[url]www.flevooware.nl/dreamweaver/[/url]

[bthouin]

Marja,

In many languages and compilers, evaluation of a condition
- either starts with the last term
- or does all evaluations regardless of result

So I guess you'll have to check first in a separate if the l_sAppVar is
empty or not.

regards
Bernard


Marja Ribbers wrote:

> Suppose I have the following test in ASP/VBscript:
>
> If (IsEmpty(l_sAppVar) Or l_sAppVar = "" Or DateDiff("d", CDate(l_sAppVar), Date()) > 0) Then
> ...
> End If
>
> then ASP complains about a type mismatch for CDate(l_sAppVar) when l_sAppVar is indeed "".
>
> This seems strange to me, because when the first or second evaluation in the test returns True, then it is not necessary anymore to evaluate the other components of the test.
> Am I missing something?
>

[Julian Roberts]

You'd need to nest the statements. eg

if boo then
if foo then

end if
end if

--
Jules
[url]http://www.charon.co.uk/charoncart[/url]
Charon Cart 3
Shopping Cart Extension for Dreamweaver MX/MX 2004

[Marja Ribbers]

I know how to work around this, but it just seemed strange to me that an Or comparison would be processed this way.

--
Marja Ribbers-de Vroed

Company website:
[url]www.webwaresystems.nl[/url]
Dreamweaver extensions:
[url]www.flevooware.nl/dreamweaver/[/url]


"Julian Roberts" <newsg@charon.co.uk> wrote in message news:d1sea7$b5e$1@forums.macromedia.com...

> You'd need to nest the statements. eg
>
> if boo then
> if foo then
>
> end if
> end if
>
> --
> Jules
> [url]http://www.charon.co.uk/charoncart[/url]
> Charon Cart 3
> Shopping Cart Extension for Dreamweaver MX/MX 2004
>
>
>