Returns the namespace URI part of the name of $arg, as an
xs:anyURI value.
fn:namespace-uri( xs:anyURIfn:namespace-uri( $arg as node()?xs:anyURIIf the argument is omitted, it defaults to the context node (.). The
behavior of the function if the argument is omitted is exactly the same as if the
context item had been passed as the argument.
If the node identified by $arg is neither an element nor an attribute node,
or if it is an element or attribute node whose expanded-QName (as determined by the
dm:node-name accessor in the )
is in no namespace, then the function returns the zero-length xs:anyURI
value.
Otherwise, the result will be the namespace URI part of the expanded-QName of the node
identified by $arg, as determined by the dm:node-name accessor
defined in ), returned as an
xs:anyURI value.
The following errors may be raised when $arg is omitted:
If the context item is absent, dynamic error
If the context item is not a node, type error .