Subject: Re: Understanding Identity Transformations
From: Dimitre Novatchev <dnovatchev@xxxxxxxxx>
Date: Sun, 13 Feb 2005 21:46:07 +1100
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On Sun, 13 Feb 2005 10:47:26 +0100, Joris Gillis <roac@xxxxxxxxxx> wrote:
> Tempore 00:33:56, die 02/13/2005 AD, hinc in
> xsl-list@xxxxxxxxxxxxxxxxxxxxxx scripsit Dimitre Novatchev
> <dnovatchev@xxxxxxxxx>:
>
> > One of the most valuable advice from even the first edition of "XSLT
> > Programmer's Reference" is always to try to use "not()" and to use
> > "!=" only when it is really necessary.
> >
>
> So which would you advise to solve the question?
>
> "@cat and not(@cat='BLUE')"
>
> or
> "@cat!='BLUE'"
Here the two comparison operators are applied on a single node, and
evaluating the the above two expressions results in the same boolean
values.
There is no confusion in using the != operator in this case.
In XPath 2.0 one would probably want to use the "ne" value comparison
operator, as it's operands can only be single values.
Cheers,
Dimitre Novatchev.
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