You can use XML Path Language (Xpath) functions to refine XPath queries and enhance the programming power and flexibility of XPath.
The functions are divided into the following 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 XPath 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. |
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.