XPath Functions

XML Path Language (XPath) functions are used to evaluate expressions.

Each function in the function library is specified using a function prototype that provides the return type, function name, and argument type. 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 groups.

Node-Set	Takes a node-set argument, returns a node set, or returns/provides information about a particular node within a node set.
String	Performs evaluations, formatting, and manipulation on string arguments.
Boolean	Evaluates the argument expressions to obtain a Boolean result.
Number	Evaluates the argument expressions to obtain a numeric result.
Microsoft Extension Functions	Microsoft extension functions to XPath that provide the ability to select nodes by XSD type. Also includes string comparison, number comparison, and date/time conversion functions.

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()]