demonstrates the default behaviour of xsl:number element : number « XSLT stylesheet « XML Tutorial

1. XML Tutorial
2. XSLT stylesheet
3. number

File: Data.xml
<?xml version="1.0" encoding="utf-8"?>
<data>
  <chapter>First Chapter</chapter>
  <chapter>
    Second Chapter
    <chapter>Subchapter 1</chapter>
    <chapter>Subchapter 2</chapter>
  </chapter>
  <chapter>
    Third Chapter
    <chapter>Subchapter A</chapter>
    <chapter>
      Subchapter B
      <chapter>sub a</chapter>
      <chapter>sub b</chapter>
    </chapter>
    <chapter>Subchapter C</chapter>
  </chapter>
</data>
File: Transform.xslt

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet
      version="1.0"
      xmlns:xsl="http://www.w3.org/1999/XSL/Transform">

    <xsl:template match="/">
      <TABLE BORDER="1">
        <TR>
          <td>Number</TH>
          <td>text</TH>
        </TR>
        <xsl:for-each select="//chapter">
          <TR>
            <TD>
              <xsl:number/>
            </TD>
            <TD>
              <xsl:value-of select="./text()"/>
            </TD>
          </TR>
        </xsl:for-each>
      </TABLE>
    </xsl:template>
</xsl:stylesheet>
Output:

<?xml version="1.0" encoding="UTF-8"?><TABLE BORDER="1"><TR><td>Number</TH><td>text</TH></TR><TR><TD>1</TD><TD>First Chapter</TD></TR><TR><TD>2</TD><TD>
    Second Chapter
    </TD></TR><TR><TD>1</TD><TD>Subchapter 1</TD></TR><TR><TD>2</TD><TD>Subchapter 2</TD></TR><TR><TD>3</TD><TD>
    Third Chapter
    </TD></TR><TR><TD>1</TD><TD>Subchapter A</TD></TR><TR><TD>2</TD><TD>
      Subchapter B
      </TD></TR><TR><TD>1</TD><TD>sub a</TD></TR><TR><TD>2</TD><TD>sub b</TD></TR><TR><TD>3</TD><TD>Subchapter C</TD></TR></TABLE>