XPath uses many integrated functions used to create and operate expression.

XPath node functions
Function Description
count() Returns total node count in a node-set.
last() Returns last node in a node-set.
position() Returns position of a node.

XPath string functions
Function Description
concat() Concatenate two strings.
contains() Checks if a string is contained in another string.
substring() Returns a substring of the asked length.
starts-with() Checks if a string beings with another string.
string.length() Returns length of a string.

XPath Boolean functions
Function Description
lang() Checks if a language is set.
not() Negates a Bollean value.

XPath number functions
Function Description
ceiling() Returns rounded upper value.
floor() Returns rounded lower value.
round() Returns rounded value to nearest Integer.
sum() Returns a added values.