[thelist] IsNumeric() vs. Val()

[.jeff]

erik,

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> From: Erik Mattheis
>
> > Val(), on the other hand, attempts to return a number
> > from a string that's passed to it.  if it can't
> > convert, it returns 0 (zero).  in and of itself, this
> > can be used as a boolean check as well since 0 is
> > false and anything else is true.  a word of caution
> > with the use of Val() though, it can't handle integers
> > of more than 10 digits long.  the following:
>
> Duh, I feel silly ... long, extended brain fart. A few
> months ago I looked at some code I think you wrote and
> saw you used Val() which I've never used so looked it
> up ... I was thinking of it in the context of using it
> to make sure something was a number before I used it in
> a query ... so in my mind Val did nothing but 0 == false
> and [anything else] == true.
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yup, that's one of the things you can do with it.

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> Is there a reason why evolt.org Val() instead of
> IsNumeric() to do this validation?
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for exactly the reason you mention.  it's one way of keeping hooligans from
monkeying with a url that passes an id and trying to append malicious sql
code.  using the Val() function removes all that crap, leaving only the
leading id.  for example:

Val('27; DELETE FROM content')

would result in

27

so, for me it serves double-duty -- data-type restriction and data-type
validation/boolean checking.

make sense?

.jeff

http://evolt.org/
jeff at members.evolt.org
http://members.evolt.org/jeff/