MarkLogic 9 Product Documentation

fn:last

fn:last() as xs:integer

Summary

Returns the context size from the dynamic context. (See Section C.2 Dynamic Context Components[XP].) If the context item is undefined, an error is raised [err:FONC0001].

Usage Notes

fn:last() returns the exact context position of the last item in the current context, so it must count all the items to do this. It is as much work as fn:count(). fn:last() is therefore best used to find the last item in a short context sequence. For example, it is useful in a path expression predicate to find the last child node of a particular element node in a particular document.

Using fn:last() in a predicate expression is not an efficient way to extract a subsequence of large item sequence. Its use for this purpose is strongly discouraged. It is much more efficient to use fn:tail() or fn:subsequence() instead.

Example

let $x := (10, 20, 30, 40, 50)
return
$x[last()]

=> 50, which is the last item in the sequence