<jfrensen@h...> wrote in message
news:1781df7e-9c44-401c-b710-2a632eef7a6a@j......
>
> > That's because Name elements aren't siblings. Each Name element is the
> > only Name element row element contains, so at the point when Name
> > element is selected, context node-set contains single Name element, so
> > last() = 1.
>
> > You need (/root/Students/row/Name)[position() = last()]
>
> Thank you, Oleg.  What confuses me is that the use of the predicate
> filter seems to change the order of evaluation of the XPath
> expression.
> That is,
>         select="/root/Students/row/Name"
> evaluates to a nodeset of two Names, and
>         select="count(/root/Students/row/Name)"
> evaluates to the number 2.
>
> Given that, I had assumed that the XPath expression
>         select="/root/Students/row/Name[position() = last()]"
> would be evaluated from left to right, yielding a nodeset, that would
> then be filtered by [position() = last()].  But this does not seem to
> be the case, if parentheses are required to change the order of
> evaluation.

You seem to be thinking of the predicate as an additional step in the path.
It isn't.  It is a modifier of the current step.

Name[position()=last()]

says get child elements with the TagName 'Name'  which happen to be the last
such in the element in the current context, a row element  (NB  'a' in the
singular).

-- 
Anthony Jones - MVP ASP/ASP.NET