XPath Functions

XPath functions are used to evaluate expressions.

Each function in the function library is specified using a function prototype, which gives the return type, the name of the function, and the type of the arguments. If an argument type is followed by a question mark, the argument is optional; otherwise, the argument is required. Function names are case sensitive.

The functions are divided into several groups:

Node-Set	Either take a node-set argument, return a node-set, or return/provide information about a particular node within a node-set.
String	Perform evaluations, formatting, and manipulation on string arguments.
Boolean	Evaluate the argument expressions to obtain a Boolean result.
Number	Evaluate the argument expressions to obtain a numeric result.
XSLT	Additions to the core XPath function library.

Examples

Find all text children of author elements:

author/text()

Find all elements that have text node or CDATA node children:

*[text()]

Find the last author for each book:

book/author[last()]