operator
key of specified? attributes (of element-expression)? [numeric-expression]
The key of attribute
operator returns the "true" name of the attribute. This is most useful when
retrieving the real name of an attribute being referenced through an alias. The name is uppercased when the SGML
declaration specifies
NAMECASE GENERAL YES
for the SGML document being processed.
When key of
is applied to attributes
, the item indexer is
required.