Extracts the first item from a sequence (XPath 1.0 first-item-only semantics).
When XPath 1.0 compatibility mode is enabled, sequences are treated as node-sets containing only the first node. This function extracts that first item.
The sequence or single value
The first item, or null if empty sequence
Extracts the first item from a sequence (XPath 1.0 first-item-only semantics).
When XPath 1.0 compatibility mode is enabled, sequences are treated as node-sets containing only the first node. This function extracts that first item.