XSLT

Name

boolean() Function — Converts its argument to a boolean value.

Synopsis

boolean boolean(
               object
               )

Inputs

An object. The object is converted to a boolean value. This conversion is described in the following subsection.

Output

The boolean value corresponding to the input object. Objects are converted to boolean values as follows:

• A number is true if and only if it is not zero, negative zero, or NaN (not a number).

• A node-set is true if and only if it is not empty.

• A string is true if and only if its length is greater than zero.

• All other datatypes are converted in a way specific to those datatypes.

Defined in

XPath section 4.3, Boolean Functions.

Example

The following example demonstrates the results of invoking the boolean() function against a variety of argument types. Here’s our XML document:

<?xml version="1.0"?>
<test>
<p>This is a test XML document used by several 
of our sample stylesheets.</p>
<question>
<text>When completed, the Eiffel Tower was the 
tallest building in the world.</text>
<true>Yes!  The Eiffel Tower was the world's 
tallest building until 1932, when
New York's Empire State Building opened. </true>
<false>No, the Eiffel Tower was the world's tallest 
building for over 30 years.</false>
</question>
</test>

We’ll process this document with the following stylesheet:

<?xml version="1.0"?> <xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"> <xsl:output method="text"/> <xsl:variable name="newline"> <xsl:text> </xsl:text> </xsl:variable> <xsl:template ...