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lang

The lang function in XQuery is used to determine whether a node's language attribute matches a specified language. This function is particularly useful for querying XML documents that use language attributes to manage multilingual content.

Syntax

fn:lang(testlang, node)

The following table describes the argument for this command:

Argument	Required/Optional	Description
testlang	Required	The language tag to test against the xml:lang attribute of the node . It typically follows language tagging conventions, such as "en", "fr", and "en-US". This parameter must be provided as a string.
node	Required	The context node whose language attribute is to be tested. If omitted, the context item from which the function is called is used by default.

Return Value

Returns

true

if the

xml:lang

attribute of the node or its nearest ancestor matches the

$testlang

value.

Returns

false

if there is no match or if

xml:lang

is absent.

Examples

The following table lists some sample XML structures, queries, and return values:

XML STRUCTURE	QUERY	OUTPUT
<book xml:lang="en"> <title>Hello World</title> </book>	fn:lang("en", /book/title)	true
<book xml:lang="fr"> <title>Bonjour le Monde</title> </book	fn:lang("en", /book/title)	false
<article xml:lang="en-US"> <section> <para>This is a paragraph.</para> </section> </article>	fn:lang("en-US")	true
<document> <content>Some text here.</content> </document>	fn:lang("en", /document/content)	false