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RE: The operator '!=' returns false when one operand doesn't exist
- From: "Michael Kay" <michael dot h dot kay at ntlworld dot com>
- To: <xsl-list at lists dot mulberrytech dot com>
- Date: Wed, 7 Aug 2002 19:42:00 +0100
- Subject: RE: [xsl] The operator '!=' returns false when one operand doesn't exist
- Reply-to: xsl-list at lists dot mulberrytech dot com
> We have an issue with the XPath '!=' operator that has
> a strange behavior when one of its operand doesn't
> exist in the instance document. It returns 'false"
> when you would expect "true" or some kind of exception
> to be raised.
A op B means "if some $a in A, $b in B satisfies $a op $b"
So if A or B is empty, the result will always be false, regardless which
operator you are using.
You nearly always want to write not(a=b) rather than a!=b.
Michael Kay
Software AG
home: Michael.H.Kay@ntlworld.com
work: Michael.Kay@softwareag.com
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