RE: Checking for the existence of a key in a querystring

Check

if (Request.QueryString["catagory"] != null) {
    label.Text = Request.QueryString["catagory"];
}


James Smith wrote:
> I am using the querystring to get information into a
page similar to
> "products.aspx?catagory=DVD".  I want some
way to check for the keys
> existence before I use it.  For example...
>
> if (check for existence) {
>     label.Text =
Request.QueryString["catagory"];
> }
>
> How would I do that?
>
>   

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>  if (Request.QueryString["catagory"] != null)
{
>
>     label.Text =
Request.QueryString["catagory"];
>  }

This looks like the way to go, in ColdFusion (my previous
language)
accessing a variable that didn't exist would have caused an
error so
you used the isDefined() function to check for existence but
if I can
just check it for NULL that will do the same job.  I also
like the
String.IsNullOrEmpty() function.  Will play with both
later.

Cheers.

--
Jay


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