XSLT - What is <xsl:for-each>?

What is `<xsl:for-each>`?

In XSLT (Extensible Stylesheet Language Transformations), the <xsl:for-each> element is used to loop through a set of nodes selected by an XPath expression.
Think of it like a for loop in other programming languages, but here it’s looping over XML nodes.

Syntax

<xsl:for-each select="XPath_expression">
    <!-- Instructions to execute for each node -->
</xsl:for-each>

select → defines which nodes you’re looping through.
Inside the loop, you can output values, apply templates, or add formatting.

Example

Suppose you have an XML file:

<books>
    <book>
        <title>XML Fundamentals</title>
        <author>Alice Johnson</author>
    </book>
    <book>
        <title>XSLT in Action</title>
        <author>Bob Smith</author>
    </book>
    <book>
        <title>Advanced XPath</title>
        <author>Carol White</author>
    </book>
</books>

XSLT using `<xsl:for-each>`

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:template match="/">
        <html>
            <body>
                <h2>Book List</h2>
                <ul>
                    <xsl:for-each select="books/book">
                        <li>
                            <xsl:value-of select="title"/> - 
                            <xsl:value-of select="author"/>
                        </li>
                    </xsl:for-each>
                </ul>
            </body>
        </html>
    </xsl:template>
</xsl:stylesheet>

Output (HTML result)

<html>
  <body>
    <h2>Book List</h2>
    <ul>
      <li>XML Fundamentals - Alice Johnson</li>
      <li>XSLT in Action - Bob Smith</li>
      <li>Advanced XPath - Carol White</li>
    </ul>
  </body>
</html>

Key Points

<xsl:for-each> iterates over all nodes matched by the XPath.
Inside the loop, you can access each node’s child elements using xsl:value-of.
You can also sort nodes using <xsl:sort> inside <xsl:for-each>.