Tom Anderson wrote:

> This may be a stupid question, but i've been banging my brain against it 
> all afternoon, and as such i'm no longer think good.
> 
> Given this XML:
> 
> <table id="mytable">
>     <tr>
>         <td class="left">port</td>
>         <td class="right">starboard</td>
>     </tr>
>     <tr>
>         <td class="left">gauche</td>
>         <td class="right">droite</td>
>     </tr>
>     <tr>
>         <td class="left">sinister</td>
>         <td class="right">dexter</td>
>     </tr>
> </table>
> 
> (a) Should this XPath expression find the cell containing 'starboard':
> 
> table[@id='mytable']/tr[1]/td[@class='right']

Yes.

> (b) Should these XPath expressions (i) mean the same thing and (ii) find 
> the cell containing 'starboard':
> 
> (1) table[@id='mytable']/tr/td[@class='right'][1]
> (2) table[@id='mytable']//td[@class='right'][1]
> (3) table[@id='mytable']//td[@class='right' and position()=1]
> 
> ?
> 
> I wrote some code on the assumption that the answer to (b)(ii) was 
> 'yes', but it didn't work. I'm not sure if this is a mistaken assumption 
> on my part, a failure to translate a correct assumption into correct 
> code, or a bug in my XPath library (Xalan 2.7.1).
> 
> My thinking had been that if you have an expression E that identifies a 
> node set, then E[n] selects the nth node of that set. 

I think you want
   (E)[n]
so e.g.
   (table[@id='mytable']/tr/td[@class='right'])[1]

-- 

	Martin Honnen
	http://msmvps.com/blogs/martin_honnen/