XPath 3.0 became a W3C Recommendation on 8 April 2014, while XPath 3.1 became a W3C Candidate Recommendation on 18 December 2014.
New features in XPath 3.0
Compared to XPath 2.0, XPath 3.0 adds the following new features:
New features in XPath 3.1
XPath 3.1 mainly adds support for array and map (associative array) 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