XPath functions

The following is an annotated list of core XPath functions and XSLT-specific additions to XPath, including a description, syntax, a list of arguments, result-type, source in the appropriate W3C Recommendation. For further information on using XPath/XSLT functions, please see the For Further Reading page.

boolean

The boolean function evaluates an expression and returns true or false.

ceiling

The ceiling function evaluates a decimal number and returns the smallest integer greater than or equal to the decimal number.

choose

The choose function returns one of the specified objects based on a boolean parameter.

concat

The concat function concatenates two or more strings and returns the resulting string.

contains

The contains function determines whether the first argument string contains the second argument string and returns boolean true or false.

count

The count function counts the number of nodes in a node-set and returns an integer.

current

The current function can be used to get the context node in an XSLT instruction.

document

The document finds a node-set in an external document, or multiple external documents, and returns the resulting node-set.

element-available

The element-available function determines if an element is available and returns true or false.

false

The false function returns boolean false.

floor

The floor function evaluates a decimal number and returns the largest integer less than or equal to the decimal number.

format-number

The format-number function evaluates a number and returns a string representing the number in a given format.

function-available

The function-available function determines if a given function is available and returns boolean true or false.

generate-id

The generate-id function generates a unique id for the first node in a given node-set and returns a string containing that id.

id

The id function finds nodes matching the given ids and returns a node-set containing the identified nodes.

key

The key function returns a node-set of nodes that have the given value for the given key.

lang

The lang function determines whether the context node matches the given language and returns boolean true or false.

last

The last function returns a number equal to the context size from the expression evaluation context.

local-name

The local-name function returns a string representing the local name of the first node in a given node-set.

name

The name function returns a string representing the QName of the first node in a given node-set.

namespace-uri

The namespace-uri function returns a string representing the namespace URI of the first node in a given node-set.

normalize-space

The normalize-space function strips leading and trailing white-space from a string, replaces sequences of whitespace characters by a single space, and returns the resulting string.

not

The not function evaluates a boolean expression and returns the opposite value.

number

The number function converts an object to a number and returns the number.

position

The position function returns a number equal to the context position from the expression evaluation context.

round

The round function returns a number that is the nearest integer to the given number.

starts-with

The starts-with checks whether the first string starts with the second string and returns true or false.

string

The string function converts the given argument to a string.

string-length

The string-length function returns a number equal to the number of characters in a given string.

substring

The substring function returns a part of a given string.

substring-after

The substring-after function returns a string that is the rest of a given string after a given substring.

substring-before

The substring-before function returns a string that is the part of a given string before a given substring.

sum

The sum function returns a number that is the sum of the numeric values of each node in a given node-set.

system-property

The system-property function returns an object representing the given system-property.

translate

The translate function evaluates a string and a set of characters to translate and returns the translated string.

true

The true function returns a boolean value of true.

unparsed-entity-url

The unparsed-entity-url() function returns the URI of the unparsed entity with the given name. This is non-XML data referenced in the DTD of the source document.