fn:exactly-one

Checks whether $arg contains exactly one item; fails if it is empty or contains multiple items.

exactly-one($arg as item()*) ➔ item()

Arguments

 

$arg

item()*

The sequence to be tested

Result

item()

Namespace

http://www.w3.org/2005/xpath-functions

Links to W3C specifications

XPath 3.1 Functions and Operators

Saxon availability

Available in XPath 2.0, XSLT 2.0, XQuery 1.0, and later versions. Available in all Saxon editions. Available for all platforms.