The result of the select expression is converted to a string. Converting
an empty node-set to a string gives you the value "".

(The semantics change in XSLT 2.0 but the end result is very similar:
absent values sort first).

Michael Kay
Software AG
home: Michael.H.Kay@xxxxxxxxxxxx
work: Michael.Kay@xxxxxxxxxxxxxx 



> -----Original Message-----
> From: owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx 
> [mailto:owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx] On Behalf Of 
> Robert P. J. Day
> Sent: 19 March 2003 04:10
> To: XSL List
> Subject:  what does xsl:sort do if "select" doesn't 
> evaluate to anything?
> 
> 
> 
>   what is the defined behavior for <xsl:sort> if the 
> "select=" expression is not satisfied by anything?
> 
>   eg., i want to process a bunch of <car> elements, sorted by 
> their engine <displacement> values, but some of the <car> 
> elements have no such element?
> 
>   i read kay pretty carefully, but his section on xsl:sort 
> didn't appear to address that specific issue.
> 
> rday
> 
> 
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> 


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