fn:string(object)
Returns the value of $arg represented as a xs:string. If no argument is supplied, the context item (.) is used as the default argument. The behavior of the function if the argument is omitted is exactly the same as if the context item had been passed as the argument.
If the context item is undefined, error [err:XPDY0002]XP is raised.
If $arg is the empty sequence, the zero-length string is returned.
If $arg is a node, the function returns the string-value of the node, as obtained using the dm:string-value accessor defined in the Section 5.13 string-value AccessorDM.
If $arg is an atomic value, then the function returns the same string as is returned by the expression " $arg cast as xs:string " (see 17 Casting).
Arguments and return type:
| Type |
Description |
| string |
The object to convert to a string |
Return type: xs:string
Examples:
| Expression |
Result |
| string((1<0)) |
false |
| string(.11) |
0.11 |
W3C Documentation reference
fn:codepoints-to-string()
Creates an xs:string from a sequence of The Unicode Standard code points. Returns the zero-length string if $arg is the empty sequence. If any of the code points in $arg is not a legal XML character, an error is raised [err:FOCH0001].
Arguments and return type:
| Type |
Description |
| xs:integer* |
$arg |
Return type: xs:string
Examples:
| Expression |
Result |
| codepoints-to-string((2309, 2358, 2378, 2325)) |
अशॊक |
| codepoints-to-string((40, 32, 865, 176, 32, 860, 662, 32, 865, 176, 41)) |
( ͡° ͜ʖ ͡°) |
W3C Documentation reference
fn:string-to-codepoints()
Returns the sequence of The Unicode Standard code points that constitute an xs:string. If $arg is a zero-length string or the empty sequence, the empty sequence is returned.
Arguments and return type:
| Type |
Description |
| xs:string* |
$arg |
Return type: xs:integer*
Examples:
| Expression |
Result |
| string-to-codepoints("Thérèse") |
(84, 104, 233, 114, 232, 115, 101) |
W3C Documentation reference
fn:compare()
Returns -1, 0, or 1, depending on whether the value of the $comparand1 is respectively less than, equal to, or greater than the value of $comparand2, according to the rules of the collation that is used.
The collation used by the invocation of this function is determined according to the rules in 7.3.1 Collations.
If either argument is the empty sequence, the result is the empty sequence.
This function, invoked with the first signature, backs up the "eq", "ne", "gt", "lt", "le" and "ge" operators on string values.
Arguments and return type:
| Type |
Description |
| xs:string? |
$comparand1 |
| xs:string? |
$comparand2 |
| xs:string |
$collation (Optional) |
Return type: xs:integer*
Examples:
| Expression |
Result |
| compare('abc', 'abc') |
0 |
| compare('abc', 'acc') |
-1 |
| compare('abc', 'acc') |
1 |
W3C Documentation reference
fn:codepoint-equal()
Returns true or false depending on whether the value of $comparand1 is equal to the value of $comparand2, according to the
Unicode code point collation.
If either argument is the empty sequence, the result is the empty sequence.
Arguments and return type:
| Type |
Description |
| xs:string? |
$comparand1 |
| xs:string? |
$comparand2 |
Return type: xs:boolean?
Examples:
| Expression |
Result |
| codepoint-equal("asdf", "asdf") |
true |
| codepoint-equal("asdf", "asdf ") |
false |
W3C Documentation reference
fn:codepoint-equal()
Accepts two or more xs:anyAtomicType arguments and casts them to xs:string. Returns the xs:string that is the concatenation of the values of its arguments after conversion. If any of the arguments is the empty sequence, the argument is treated as the zero-length string.
The fn:concat function is specified to allow two or more arguments, which are concatenated together. This is the only function specified in this document that allows a variable number of arguments. This capability is retained for compatibility with [XML Path Language (XPath) Version 1.0].
Arguments and return type:
| Type |
Description |
| xs:anyAtomicType? |
$arg1 |
| xs:anyAtomicType? |
$arg2 |
| xs:anyAtomicType? |
$arg... (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| concat('un', 'grateful') |
ungrateful |
| concat('Thy ', (), 'old ', "groans", "", ' ring', ' yet', ' in', ' my', ' ancient',' ears.') |
Thy old groans ring yet in my ancient ears. |
| fn:concat('Ciao!',()) |
Ciao! |
W3C Documentation reference
fn:string-join()
Returns a xs:string created by concatenating the members of the $arg1 sequence using $arg2 as a separator. If the value of $arg2 is the zero-length string, then the members of $arg1 are concatenated without a separator.
If the value of $arg1 is the empty sequence, the zero-length string is returned.
Arguments and return type:
| Type |
Description |
| xs:string* |
$arg1 |
| xs:string |
$arg2 |
Return type: xs:string
Examples:
| Expression |
Result |
| string-join(('Now', 'is', 'the', 'time', '...'), ' ') |
Now is the time ... |
| string-join(('Blow, ', 'blow, ', 'thou ', 'winter ', 'wind!'), '') |
Blow, blow, thou winter wind! |
W3C Documentation reference
fn:substring()
Returns the portion of the value of $sourceString beginning at the position indicated by the value of $startingLoc and continuing for the number of characters indicated by the value of $length. The characters returned do not extend beyond $sourceString. If $startingLoc is zero or negative, only those characters in positions greater than zero are returned.
More specifically, the three argument version of the function returns the characters in $sourceString whose position $p obeys:
fn:round($startingLoc) <= $p < fn:round($startingLoc) + fn:round($length)
The two argument version of the function assumes that $length is infinite and returns the characters in $sourceString whose position $p obeys:
fn:round($startingLoc) <= $p < fn:round(INF)
In the above computations, the rules for op:numeric-less-than() and op:numeric-greater-than() apply.
If the value of $sourceString is the empty sequence, the zero-length string is returned.
Note:
The first character of a string is located at position 1, not position 0.
Arguments and return type:
| Type |
Description |
| xs:string? |
$sourceString |
| xs:double |
$startingLoc |
| xs:double |
$length (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| substring("motor car", 6) |
" car" |
| substring("metadata", 4, 3) |
ada |
W3C Documentation reference
fn:string-length()
Returns an xs:integer equal to the length in characters of the value of $arg.
If the value of $arg is the empty sequence, the xs:integer 0 is returned.
If no argument is supplied, $arg defaults to the string value (calculated using fn:string()) of the context item (.). If no argument is supplied and the context item is undefined an error is raised: [err:XPDY0002].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg (Optional) |
Return type: xs:integer
Examples:
| Expression |
Result |
| string-length("Harp not on that string, madam; that is past.") |
45 |
| string-length(()) |
0 |
W3C Documentation reference
fn:normalize-space()
Returns the value of $arg with whitespace normalized by stripping leading and trailing whitespace and replacing sequences of one or more than one whitespace character with a single space, #x20.
If the value of $arg is the empty sequence, returns the zero-length string.
If no argument is supplied, then $arg defaults to the string value (calculated using fn:string()) of the context item (.). If no argument is supplied and the context item is undefined an error is raised: [err:XPDY0002].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| normalize-space(" The wealthy curled darlings of our nation. ") |
The wealthy curled darlings of our nation. |
| normalize-space(()) |
"" |
W3C Documentation reference
fn:normalize-unicode()
Returns the value of $arg normalized according to the normalization criteria for a normalization form identified by the value of $normalizationForm. The effective value of the $normalizationForm is computed by removing leading and trailing blanks, if present, and converting to upper case.
If the value of $arg is the empty sequence, returns the zero-length string.
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg |
| xs:string |
$normalizationForm (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| normalize-unicode("test ") |
test |
W3C Documentation reference
fn:upper-case()
Returns the value of $arg after translating every character to its upper-case correspondent as defined in the appropriate case mappings section in the Unicode standard [The Unicode Standard]. For versions of Unicode beginning with the 2.1.8 update, only locale-insensitive case mappings should be applied. Beginning with version 3.2.0 (and likely future versions) of Unicode, precise mappings are described in default case operations, which are full case mappings in the absence of tailoring for particular languages and environments. Every lower-case character that does not have an upper-case correspondent, as well as every upper-case character, is included in the returned value in its original form.
If the value of $arg is the empty sequence, the zero-length string is returned.
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg |
Return type: xs:string
Examples:
| Expression |
Result |
| upper-case("abCd0") |
ABCD0 |
W3C Documentation reference
fn:lower-case()
Returns the value of $arg after translating every character to its lower-case correspondent as defined in the appropriate case mappings section in the Unicode standard [The Unicode Standard]. For versions of Unicode beginning with the 2.1.8 update, only locale-insensitive case mappings should be applied. Beginning with version 3.2.0 (and likely future versions) of Unicode, precise mappings are described in default case operations, which are full case mappings in the absence of tailoring for particular languages and environments. Every upper-case character that does not have a lower-case correspondent, as well as every lower-case character, is included in the returned value in its original form.
If the value of $arg is the empty sequence, the zero-length string is returned.
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg |
Return type: xs:string
Examples:
| Expression |
Result |
| lower-case("abCd0") |
abcd0 |
W3C Documentation reference
fn:lower-case()
Returns the value of $arg modified so that every character in the value of $arg that occurs at some position N in the value of $mapString has been replaced by the character that occurs at position N in the value of $transString.
If the value of $arg is the empty sequence, the zero-length string is returned.
Every character in the value of $arg that does not appear in the value of $mapString is unchanged.
Every character in the value of $arg that appears at some position M in the value of $mapString, where the value of $transString is less than M characters in length, is omitted from the returned value. If $mapString is the zero-length string $arg is returned.
If a character occurs more than once in $mapString, then the first occurrence determines the replacement character. If $transString is longer than $mapString, the excess characters are ignored.
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg |
| xs:string |
$mapString |
| xs:string |
$mapString |
Return type: xs:string
Examples:
| Expression |
Result |
| translate("bar","abc","ABC") |
BAr |
| translate("--aaa--","abc-","ABC") |
AAA |
| translate("abcdabc", "abc", "AB") |
ABdAB |
W3C Documentation reference
fn:encode-for-uri()
This function encodes reserved characters in an xs:string that is intended to be used in the path segment of a URI. It is invertible but not idempotent. This function applies the URI escaping rules defined in section 2 of [RFC 3986] to the xs:string supplied as $uri-part. The effect of the function is to escape reserved characters. Each such character in the string is replaced with its percent-encoded form as described in [RFC 3986].
If $uri-part is the empty sequence, returns the zero-length string.
All characters are escaped except those identified as "unreserved" by [RFC 3986], that is the upper- and lower-case letters A-Z, the digits 0-9, HYPHEN-MINUS ("-"), LOW LINE ("_"), FULL STOP ".", and TILDE "~".
Note that this function escapes URI delimiters and therefore cannot be used indiscriminately to encode "invalid" characters in a path segment.
Since [RFC 3986] recommends that, for consistency, URI producers and normalizers should use uppercase hexadecimal digits for all percent-encodings, this function must always generate hexadecimal values using the upper-case letters A-F.
Arguments and return type:
| Type |
Description |
| xs:string? |
$uri-part |
Return type: xs:string
Examples:
| Expression |
Result |
| encode-for-uri("https://www.google.com") |
"https%3A%2F%2Fwww.
google.com" |
| concat("http://www.example.com/", encode-for-uri("~bébé")) |
http://www.example.com/
~b%C3%A9b%C3%A9 |
| concat("http://www.example.com/", encode-for-uri("100% organic")) |
http://www.example.com/
100%25%20organic |
W3C Documentation reference
fn:iri-to-uri()
This function converts an xs:string containing an IRI into a URI according to the rules spelled out in Section 3.1 of [RFC 3987]. It is idempotent but not invertible.
If $iri contains a character that is invalid in an IRI, such as the space character (see note below), the invalid character is replaced by its percent-encoded form as described in [RFC 3986] before the conversion is performed.
If $iri is the empty sequence, returns the zero-length string.
Arguments and return type:
| Type |
Description |
| xs:string? |
$iri |
Return type: xs:string
Examples:
| Expression |
Result |
| iri-to-uri ("http://www.example.com/00/Weather/CA/Los%20Angeles#ocean") |
"http://www.example.com/00/
Weather/CA/Los%20Angeles#ocean" |
| iri-to-uri ("http://www.example.com/~bébé") |
http://www.example.com/
~b%C3%A9b%C3%A9 |
W3C Documentation reference
fn:escape-html-uri()
This function escapes all characters except printable characters of the US-ASCII coded character set, specifically the octets ranging from 32 to 126 (decimal). The effect of the function is to escape a URI in the manner html user agents handle attribute values that expect URIs. Each character in $uri to be escaped is replaced by an escape sequence, which is formed by encoding the character as a sequence of octets in UTF-8, and then representing each of these octets in the form %HH, where HH is the hexadecimal representation of the octet. This function must always generate hexadecimal values using the upper-case letters A-F.
If $uri is the empty sequence, returns the zero-length string.
Note:
The behavior of this function corresponds to the recommended handling of non-ASCII characters in URI attribute values as described in [HTML 4.0] Appendix B.2.1.
Arguments and return type:
| Type |
Description |
| xs:string? |
$uri |
Return type: xs:string
Examples:
| Expression |
Result |
| escape-html-uri("http://www.example.com/00/Weather/CA/Los Angeles#ocean") |
http://www.example.com/00/Weather/CA/Los Angeles#ocean |
W3C Documentation reference
fn:contains()
Returns an xs:boolean indicating whether or not the value of $arg1 contains (at the beginning, at the end, or anywhere within) at least one sequence of collation units that provides a minimal match to the collation units in the value of $arg2, according to the collation that is used.
If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable collation units, it is interpreted as the zero-length string.
If the value of $arg2 is the zero-length string, then the function returns true.
If the value of $arg1 is the zero-length string, the function returns false.
The collation used by the invocation of this function is determined according to the rules in 7.3.1 Collations. If the specified collation does not support collation units an error ·may· be raised [err:FOCH0004].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg1 |
| xs:string? |
$arg2 |
| xs:string? |
$collation (Optional) |
Return type: xs:boolean
Examples:
| Expression |
Result |
| contains( "tattoo", "tat") |
true |
| contains( "tattoo", "ttt") |
false |
| contains ( "", ()) |
true |
W3C Documentation reference
fn:starts-with()
Returns an xs:boolean indicating whether or not the value of $arg1 starts with a sequence of collation units that provides a match to the collation units of $arg2 according to the collation that is used.
If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable collation units, it is interpreted as the zero-length string.
If the value of $arg2 is the zero-length string, then the function returns true. If the value of $arg1 is the zero-length string and the value of $arg2 is not the zero-length string, then the function returns false.
The collation used by the invocation of this function is determined according to the rules in 7.3.1 Collations. If the specified collation does not support collation units an error ·may· be raised [err:FOCH0004].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg1 |
| xs:string? |
$arg2 |
| xs:string? |
$collation (Optional) |
Return type: xs:boolean
Examples:
| Expression |
Result |
| starts-with( "tattoo", "tat") |
true |
| starts-with( "tattoo", "ttt") |
false |
| starts-with ( "", ()) |
true |
W3C Documentation reference
fn:ends-with()
Returns an xs:boolean indicating whether or not the value of $arg1 starts with a sequence of collation units that provides a match to the collation units of $arg2 according to the collation that is used.
If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable collation units, it is interpreted as the zero-length string.
If the value of $arg2 is the zero-length string, then the function returns true. If the value of $arg1 is the zero-length string and the value of $arg2 is not the zero-length string, then the function returns false.
The collation used by the invocation of this function is determined according to the rules in 7.3.1 Collations. If the specified collation does not support collation units an error ·may· be raised [err:FOCH0004].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg1 |
| xs:string? |
$arg2 |
| xs:string? |
$collation (Optional) |
Return type: xs:boolean
Examples:
| Expression |
Result |
| ends-with( "tattoo", "too") |
true |
| ends-with( "tattoo", "tatoo") |
false |
| ends-with ((), ()) |
true |
W3C Documentation reference
fn:substring-before()
Returns the substring of the value of $arg1 that precedes in the value of $arg1 the first occurrence of a sequence of collation units that provides a minimal match to the collation units of $arg2 according to the collation that is used.
If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable collation units, it is interpreted as the zero-length string.
If the value of $arg2 is the zero-length string, then the function returns the zero-length string.
If the value of $arg1 does not contain a string that is equal to the value of $arg2, then the function returns the zero-length string.
The collation used by the invocation of this function is determined according to the rules in 7.3.1 Collations If the specified collation does not support collation units an error ·may· be raised [err:FOCH0004].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg1 |
| xs:string? |
$arg2 |
| xs:string? |
$collation (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| substring-before( "tattoo", "too") |
tat |
| substring-before( "tattoo", "tat") |
<empty string> |
W3C Documentation reference
fn:substring-after()
Returns the substring of the value of $arg1 that follows in the value of $arg1 the first occurrence of a sequence of collation units that provides a minimal match to the collation units of $arg2 according to the collation that is used.
If the value of $arg1 or $arg2 is the empty sequence, or contains only ignorable collation units, it is interpreted as the zero-length string.
If the value of $arg2 is the zero-length string, then the function returns the value of $arg1.
If the value of $arg1 does not contain a string that is equal to the value of $arg2, then the function returns the zero-length string.
The collation used by the invocation of this function is determined according to the rules in 7.3.1 Collations If the specified collation does not support collation units an error ·may· be raised [err:FOCH0004].
Arguments and return type:
| Type |
Description |
| xs:string? |
$arg1 |
| xs:string? |
$arg2 |
| xs:string? |
$collation (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| substring-after( "tattoo", "too") |
<empty string> |
| substring-after( "tattoo", "tat") |
too |
W3C Documentation reference
fn:matches()
The function returns true if $input matches the regular expression supplied as $pattern as influenced by the value of $flags, if present; otherwise, it returns false.
The effect of calling the first version of this function (omitting the argument $flags) is the same as the effect of calling the second version with the $flags argument set to a zero-length string. Flags are defined in 7.6.1.1 Flags.
If $input is the empty sequence, it is interpreted as the zero-length string.
Unless the metacharacters ^ and $ are used as anchors, the string is considered to match the pattern if any substring matches the pattern. But if anchors are used, the anchors must match the start/end of the string (in string mode), or the start/end of a line (in multiline mode).
An error is raised [err:FORX0002] if the value of $pattern is invalid according to the rules described in section 7.6.1 Regular Expression Syntax.
An error is raised [err:FORX0001] if the value of $flags is invalid according to the rules described in section 7.6.1 Regular Expression Syntax.
Arguments and return type:
| Type |
Description |
| xs:string? |
$input |
| xs:string |
$pattern |
| xs:string |
$flags (Optional) |
Return type: xs:boolean
Examples:
| Expression |
Result |
| matches("abracadabra", "bra") |
true |
| matches("abracadabra", "^a.*a$") |
false |
W3C Documentation reference
fn:replace()
The function returns the xs:string that is obtained by replacing each non-overlapping substring of $input that matches the given $pattern with an occurrence of the $replacement string.
The effect of calling the first version of this function (omitting the argument $flags) is the same as the effect of calling the second version with the $flags argument set to a zero-length string. Flags are defined in 7.6.1.1 Flags.
The $flags argument is interpreted in the same manner as for the fn:matches() function.
If $input is the empty sequence, it is interpreted as the zero-length string.
If two overlapping substrings of $input both match the $pattern, then only the
first one (that is, the one whose first character comes first in the $input string) is replaced.
Within the $replacement string, a variable $N may be used to refer to the substring captured by the Nth parenthesized sub-expression in the regular expression. For each match of the pattern, these variables are assigned the value of the content matched by the relevant sub-expression, and the modified replacement string is then substituted for the characters in $input that matched the pattern. $0 refers to the substring captured by the regular expression as a whole.
Arguments and return type:
| Type |
Description |
| xs:string? |
$input |
| xs:string |
$pattern |
| xs:string |
$replacement |
| xs:string |
$flags (Optional) |
Return type: xs:string
Examples:
| Expression |
Result |
| replace("abracadabra", "bra", "*") |
a*cada* |
| replace("abracadabra", "a.*a", "*") |
* |
| replace("AAAA", "A+", "b") |
b |
W3C Documentation reference
fn:tokenize()
This function breaks the $input string into a sequence of strings, treating any substring that matches $pattern as a separator. The separators themselves are not returned.
The effect of calling the first version of this function (omitting the argument $flags) is the same as the effect of calling the second version with the $flags argument set to a zero-length string. Flags are defined in 7.6.1.1 Flags.
The $flags argument is interpreted in the same way as for the fn:matches() function.
If $input is the empty sequence, or if $input is the zero-length string, the result is the empty sequence.
If the supplied $pattern matches a zero-length string, that is, if fn:matches("", $pattern, $flags) returns true, then an error is raised: [err:FORX0003].
If a separator occurs at the start of the $input string, the result sequence will start with a zero-length string. Zero-length strings will also occur in the result sequence if a separator occurs at the end of the $input string, or if two adjacent substrings match the supplied $pattern.
Arguments and return type:
| Type |
Description |
| xs:string? |
$input |
| xs:string |
$pattern |
| xs:string |
$flags (Optional) |
Return type: xs:string*
Examples:
| Expression |
Result |
| tokenize("The cat sat on the mat", "\s+") |
("The", "cat", "sat", "on", "the", "mat") |
| tokenize("1, 15, 24, 50", ",\s*") |
("1", "15", "24", "50") |
| tokenize("1,15,,24,50,", ",") |
("1", "15", "", "24", "50", "") |
W3C Documentation reference