not

The not function evaluates a boolean expression and returns the opposite value.

Syntax

not( expression )

Arguments

expression

The expression is evaluated exactly as if it were passed as an argument to the boolean() function.

Returns

True for an expression that evaluates to false; false for an expression that evaluates to true.

Notes

  • This function should behave similarly to the boolean() function except that it returns the opposite value.
  • You can test if an element doesn't have some attribute.

    xml

    <xsl:for-each match="//a[not(@name and @name = 'badname')]">
      <!-- iterates over any <a> element in the document, that
            either has no 'name' attribute at all, or it has one,
            but its value is not "badname". -->
    </xsl:template>
    

Defined

Gecko support

Supported.