XPath 3


XPath 3 is the latest version of the XML Path Language, a query language for selecting nodes in XML documents. It supersedes XPath 1.0 and XPath 2.0.
XPath 3.0 became a W3C Recommendation on 8 April 2014, while XPath 3.1 became a W3C Recommendation on 21 March 2017.

New features in XPath 3.0

Compared to XPath 2.0, XPath 3.0 adds the following new features:
; Inline function expressions
; Dynamic function calls
; Union types
; Namespace literals
; String concatenation operator
; Mapping operator

New features in XPath 3.1

XPath 3.1 mainly adds support for array and map data types. These types and their associated functionality are intended to ease working with JSON data.
Another innovation is the arrow operator => for function chaining. For example, the XPath 2.0 expression
can now be written