count() Function  
Counts the number of nodes in a given node-set.
 
Inputs

A node-set.
 
Output

The number of nodes in the node-set.

 
Defined in

XPath section 4.1, Node Set Functions.
 
Examples

Here's the XML document we'll use to illustrate the count() function:

<?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>You're correct!  The Eiffel Tower was the 
    world's tallest building until 1930.</true>
    <false>No, the Eiffel Tower was the world's 
    tallest building for over 30 years.</false>
  </question>
  <question>
    <text>New York's Empire State Building knocked 
    the Eiffel Tower from its pedestal.</text>
    <true>No, that's not correct.</true>
    <false>Correct!  New York's Chrysler Building, 
    completed in 1930, became the world's tallest.</false>
  </question>
</test>

Here's a stylesheet that illustrates the count() function:

<?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 match="/">
    <xsl:value-of select="$newline"/>
    <xsl:text>Tests of the count() function:</xsl:text>

    <xsl:value-of select="$newline"/>
    <xsl:value-of select="$newline"/>
    <xsl:text>   count(/test)=</xsl:text>
    <xsl:value-of select="count(/test)"/>
    <xsl:value-of select="$newline"/>
    <xsl:text>   count(/true)=</xsl:text>
    <xsl:value-of select="count(/true)"/>
    <xsl:value-of select="$newline"/>
    <xsl:text>   count(//true)=</xsl:text>
    <xsl:value-of select="count(//true)"/>
    <xsl:value-of select="$newline"/>
    <xsl:text>   count(//test|//true|//text)=</xsl:text>
    <xsl:value-of select="count(//test|//true|//text)"/>
    <xsl:value-of select="$newline"/>
    <xsl:variable name="numberOfQuestions" select="count(/test/question)"/>
    <xsl:for-each select="/test/question">
      <xsl:text>   This is question number </xsl:text>
      <xsl:value-of select="position()"/>
      <xsl:text> of </xsl:text>
      <xsl:value-of select="$numberOfQuestions"/>

      <xsl:value-of select="$newline"/>
    </xsl:for-each>
  </xsl:template>

</xsl:stylesheet>

Here are the results of our stylesheet:


Tests of the count() function:

   count(/test)=1
   count(/true)=0
   count(//true)=2
   count(//test|//true|//text)=5
   This is question number 1 of 2
   This is question number 2 of 2

The first four invocations of the count() function merely use XPath expressions to count something in the XML document. The last use of count() counts the number of <question> elements in our document and stores that value in a variable. Generating text like item x of y is a common technique; our use of the count() and position() is how this generation is commonly done.