xslt-lab/site/content/xslt/functions/xpath-qname.md

title, description, date, version, versionLabel, category, syntax, tags

title	description	date	version	versionLabel	category	syntax	tags
QName()	Constructs an xs:QName value from a namespace URI and a lexical qualified name string.	2026-04-18T00:00:00Z	2.0	XSLT 2.0	QName function	QName(namespace-uri, lexical-qname)	xslt reference xpath xslt2

Description

QName() creates an xs:QName value by combining a namespace URI string with a lexical qualified name (which may include a prefix). This is the primary way to construct typed QName values dynamically in XPath 2.0.

The resulting xs:QName can be used for namespace-aware name comparisons, passed to functions like node-name(), and used with element-available() or type-available().

Parameters

Parameter	Type	Required	Description
namespace-uri	xs:string?	Yes	The namespace URI. Pass an empty string "" for no namespace.
lexical-qname	xs:string	Yes	A lexical qualified name, optionally including a prefix (e.g., "xs:date" or "item").

Return value

xs:QName — the constructed QName with the given namespace URI, local name, and prefix.

Examples

Compare a node's name to a constructed QName

Input XML:

<?xml version="1.0" encoding="UTF-8"?>
<root xmlns:app="http://example.com/app">
  <app:widget type="button">Click me</app:widget>
  <app:widget type="text">Enter value</app:widget>
  <other:item xmlns:other="http://example.com/other">Extra</other:item>
</root>

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/root">
    <widgets>
      <xsl:copy-of select="*[node-name(.) eq QName('http://example.com/app', 'app:widget')]"/>
    </widgets>
  </xsl:template>
</xsl:stylesheet>

Output:

<widgets>
  <app:widget xmlns:app="http://example.com/app" type="button">Click me</app:widget>
  <app:widget xmlns:app="http://example.com/app" type="text">Enter value</app:widget>
</widgets>

Dynamically create an element with a qualified name

Stylesheet:

<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="2.0"
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
  xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xsl:output method="xml" indent="yes"/>

  <xsl:template match="/items/item">
    <xsl:variable name="qn" select="QName('http://example.com/out', concat('out:', @type))"/>
    <xsl:element name="{local-name-from-QName($qn)}"
                 namespace="{namespace-uri-from-QName($qn)}">
      <xsl:value-of select="."/>
    </xsl:element>
  </xsl:template>
</xsl:stylesheet>

Notes

• The prefix in the lexical-qname argument is stored in the xs:QName value but has no significance beyond readability — namespace-aware comparison uses the namespace URI and local name only.
• If namespace-uri is empty ("") and the lexical name contains a colon, an error is raised.
• QName() is the typed-value complement of resolve-QName(), which resolves namespace prefixes from an element's in-scope namespaces.

See also

• local-name-from-QName()
• namespace-uri-from-QName()
• prefix-from-QName()
• resolve-QName()