fn:prefix-from-QName - XPath XQuery Reference

Returns the prefix component of the supplied QName.

fn:prefix-from-QName(

$arg as xs:QName?

) as xs:NCName?

This function is deterministic, context-independent, and focus-independent.

If $arg is the empty sequence the function returns the empty sequence.

If $arg has no prefix component the function returns the empty sequence.

Otherwise, the function returns an xs:NCName representing the prefix component of $arg.

XPath/XQuery prefix-from-QName function