XSLT, 2nd Edition

Name

not()

Returns the negation of its argument. If the argument is not a boolean value already, it is converted to a boolean value using the rules described in the boolean() function entry.

Syntax

[1.0] boolean not(boolean)
[2.0] xs:boolean not(item()*)

Inputs

A boolean value, or more commonly, an XPath expression that evaluates to a boolean value.

Output

false if the input parameter is true; true if the input parameter is false.

Defined in

[1.0] XPath section 4.3, “Boolean Functions.”

[2.0] XQuery 1.0 and XPath 2.0 Functions and Operators section 9.3, “Functions on Boolean Values.”

Example

To demonstrate the not() function, we’ll use the same stylesheet and XML document we used for the boolean() function. Here’s our XML document:

<?xml version="1.0" encoding="utf-8"?>
<!-- chocolate.xml -->
<report month="8" year="2006">
  <title>Chocolate bar sales</title>
  <brand>
    <name>Lindt</name>
    <units>27408</units>
  </brand>
  <brand>
    <name>Callebaut</name>
    <units>8203</units>
  </brand>
  <brand>
    <name>Valrhona</name>
    <units>22101</units>
  </brand>
  <brand>
    <name>Perugina</name>
    <units>14336</units>
  </brand>
  <brand>
    <name>Ghirardelli</name>
    <units>19268</units>
  </brand>
</report>

We’ll process this document with the following stylesheet, which uses not() instead of boolean(). The boolean() function converts its argument to a boolean value; the not() function implicitly uses boolean() to convert its argument to a boolean value, and then negates it.

<?xml version="1.0"?>
<!-- not.xsl --> <xsl:stylesheet version="1.0" ...