Wikifunctions:Catalogue/String operations

See also: WF:Catalogue/Character operations

These are functions that deal with String (Z6): A sequence of characters, and one of the fundamental Z4/Types available in the Wikifunctions system.

Evaluation

These functions perform simple tests on a text string to tell you if something else needs to be done, or they already are in an expected format.

Empty strings

• is empty string (Z10008): true if the input string is strictly empty, even without any non-printing characters, and false otherwise may return False for a non-string argument: T417631
  • debug (Z12941): prints the non-empty string passed to it as a debug and returns true, if empty returns false
• is not empty string (Z24331): returns true if the string in the argument is not blank
• fallback if string is empty (Z11082): returns a fallback string if the value is empty, and the value itself if not
  • fallback string if error, empty or not a string (Z32556): returns the given string unless it is empty or not a string (including when it is an error), when the default is returned

Case and character types

• is string blank (Z10083): Checks if a string just contains whitespaces
• is numeric (Z10715): Checks if a string contains only numeric characters
  • contains square brackets (Z28182): true if the string contains either "[" or "]" characters
• is uppercase (Z10336): checks if string is uppercase (equal to its own uppercase - so blanks and empty strings count)
• has and is uppercase (Z11349): checks if string has and is uppercase (blanks and strings without letters don't count)
• is lowercase (Z10346): checks if string is all lowercase
• has and is lowercase (Z11383): checks if string has and is lowercase (blanks and strings without letters don't count)
• is title case (Z10375): checks if string is in title case
• is pascal case (Z10363): Checks whether a string is in PascalCase.
• is camel case (Z10897): Checks whether a string is in camelCase
• is snake case (Z10324): Checks whether a string is in snake_case.
• is kebab case (Z25592): Checks whether a string is in kebab-case.

• has specified chars paired (Z11678): check if a string has correctly paired chars (for example: brackets). Specifying left and right chars (brackets) in sequence
• has all brackets paired (Z11684): check for pairing of all possible left-right paired characters, feel free to extend
• is pangram (Latin alphabet) (Z12626): checks whether a string of characters possesses every letter from the Latin alphabet at least once

Other

• is a palindrome (Z10096): test if a string is the same when read forward and backward (see Z10553 for one with Unicode grapheme support)
• has double letter (Z19170): tests whether the string has any letter (case sensitive) used twice in a row
• is square-free (Z19191): Combinatorial term. A word that avoids the pattern XX where X is any non-empty sequence of letters
• Is it a valid ISO 6709 code (Z19217): checks if a string matches ISO 6709.
• is ISO 639-1 language code (Z13482): validates whether a string is a valid ISO 639-1 language code
• is ISO 639-2 language code (Z14083): validates whether a string is a valid ISO 639-2 language code
• is heterogram (Z11573): True if no character occurs more than once

Properties and metrics

Length

• string length (Z11040): Return the length of this string
• string length in UTF-8 code units (Z17036): Return the length of this string in UTF-8 code units
• string length in UTF-16 code units (Z17030): Return the length of this string in UTF-16 code units

Distance

• hamming distance between two strings (Z11328): the strings should be of equal length, otherwise will return -1
• Levenshtein distance (Z10393): a metric for measuring the difference between two sequences by calculating the minimum number of single-character edits between 2 strings.

Get specific characters or substrings

Anywhere in the string

• get Nth code point of String (Z24472): counting each codepoint from 1 returns 0x0015 (negative acknowledge) if index out-of-bounds
  • get Nth character of a string (Z14244): counting each codepoint as a character, counting from 1
• substring by index (0-indexed) (Z28630): Description missing
  • first N characters of string (Z14592): returns a substring from the beginning of a specified string up to a number of characters

At the start

• first grapheme cluster of String (Z31145): Description missing
  • get first Code point of String (Z32065): Description missing
  • get first character of string (Z10901): returns the first character of a string
• first N code points (Z15996): returns a string containing the specified number of character code points
• str left (Z22344): Gives the resultant <count> of characters creating a substring of characters from the start of the trimmed string. Duplicates string as needed. (same as Template:Str left on EnWp)

At the end

• get last Code point of String (Z31845): Description missing
  • get last character of string (Z11060): returns the last character of a string
• final N characters of string (Z14460): return only the last N characters of the initial string
• character Nth from the end of the string (Z14463): return is a string type

Comparison

Comparison functions for String (Z6)

s1 ≠ s2 Q110013332	string inequality (Z10379)
s1 ⊇ s2 Q1332977	has substring (Z10070)
s1 = s2 Q842346	string equality (Z866)		s1 ≈ s2 Q26161438	case-insensitive string equality (Z10539)
s ≠ <empty>	is not empty string (Z24331)
s = <empty>	is empty string (Z10008)		s ≈ <empty>	is string blank (Z10083)

Equality

• string equality (Z866): True if the first string and the second string are the same
• case-insensitive string equality (Z10539): returns true if both strings are the same if converted to lowercase
• string inequality (Z10379): true if two text strings are not exactly equal
• echo string except for specific replacement (Z18898): returns the same string, unless it matches a specific string when it returns a specific string

Substrings and characters

• string starts with (Z10615): returns true if the substring exists at the beginning of the string
• string ends with (Z10618): true if the substring exists at the end of the string
• string only has characters from alphabet (Z11693): check if all of the characters in the tested string are from the alphabet string
• common codepoints in strings (Z14483): true if the two strings contain any codepoints (~characters) in common
• is pangram of alphabet (Z13119): check if the string uses every letter of a specified (lowercase) alphabet
• is anagram (simple) (Z10973): test if the same characters at the same number of times are used in two strings (characters must be exact code points).
• is subword of string (Z19177): the subword is contained (in order) in the string, but may be interspersed with other letters

Length

• strings equal length (Z11690): checks if the two input strings are of equal length
• longer of two Strings (Z11519): Returns the longer of two strings. If equal, defaults to returning the first.

String search

• has substring (Z10070): Check if a substring exists within another string. Case-sensitive. For a case-insensitivity support see: Z22812
• count substrings (Z14450): returns the number of times a substring occurs in a string
• position (1..=N) of first matching substring (Z31826): returns the earliest position in the first string at which the second string begins. or 0 if the first string doesn't contain the second; only identical code points count as a match
  • first index (1..=N) of character in String (Z31268): returns 0 if not present

Transformation

These perform character replacements and other basic operations.

Add characters

To the start and end

• wrap string (Z11145): add wrapper text to the start and end of a string

To the end (suffix)

• add suffix "as" (Z27528): Description missing
• add suffix "es" (Z27529): Description missing

If the string doesn't already end with a specific suffix

• add suffix to string if it does not already end with the suffix (Z17973): E.g. testing + ing -> testing

Language-specific suffixes

• add suffix "ns" to string if it does not end with "ns" (Z18066): for Swedish
• add suffix "en" to string if it does not end with "en" (Z18050): Description missing
• add suffix "ets" to string if not end with "ets" (Z18042): Description missing
• add suffix "ens" to string if it does not end with "ens" (Z18039): Description missing
• add suffix "enas" to string if it does not end with "enas" (Z18036): E.g. huvud -> huvudenas
• add suffix "s" to string if it does not already end with "s" (Z18020): E.g. test -> tests
• add suffix "ts" to string if it does not already end with "ts" (Z18017): Description missing
• add suffix "nas" to string if it does not already end with "nas" (Z17952): Description missing
• add suffix "rnas" to string if it does not end with "rnas" (Z17942): E.g. fiende -> fiendernas
• add suffix "rna" to string if it does not end with "rna" (Z17939): E.g. fiende -> fienderna
• add suffix "r" to string if it does not end with "r" (Z17749): E.g. fiende -> fiender
• add suffix "t" to string if it does not end with "t" (Z17904): E.g. äpple -> äpplet
• add suffix "a" to string if it does not end in "a" (Z17948): Description missing
• add suffix "n" to string if it does not already end with "n" (Z17791): E.g. äpple -> äpplen

Replace characters

Anywhere in the string

• replace all substrings (Z10075): finds and replaces all instances of a substring in an input string
• replace character set (Z14613): replaces each character of the first string that appears in the second string with the corresponding character in the third string
• replace Nth character with substitution (Z29506): Description missing
• left/inner/right mark replacement (Z11492): replaces the same mark (or substring) in a string with different replacements depending on position
• general positional mark replacement (Z11501): a generalisation of Z11492 to allow different spacers and specify isolated replacement

At the end (suffix)

• replace at end (Z11178): replaces suffix with replacement if input ends with suffix; if not, returns input unchanged
• replace last character (Z27159): Description missing

Language-specific suffixes

• replace suffix "a" with "ors" (Z18092): E.g. gata -> gators
• replace suffix "a" with "ons" (Z18026): Description missing
• replace suffix "a" with "on" (Z17827): E.g. öga -> ögon
• replace suffix "a" with "orna" (Z17915): E.g. gata -> gatorna
• replace suffix "a" with "ornas" (Z17918): E.g. gata -> gatornas
• replace suffix "o" with "a" (Z27517): Description missing
• replace suffix "o" with "as" (Z27522): Description missing
• replace suffix "m" with "ns" (Z27525): Description missing
• replace suffix "ão" with "ões" (Z27534): Description missing
• replace suffix "ês" with "eses" (Z27535): Description missing
• replace suffix "ês" with "esa" (Z27536): Description missing
• replace suffix "ês" with "esas" (Z27537): Description missing
• replace suffix "l" with "is" (Z27546): Description missing

Delete or discard characters

Anywhere in the string

• remove regular spaces (Z10052): remove all regular spaces (U+0020) from a string
• remove characters in character range (Z11531): strips all characters from a codepoint block from a string
• remove characters in unicode range (Z14119): strips all characters from a codepoint block (specified by unicodes) from a string
• remove interpunction (Z11193): remove all interpunction characters
• remove all characters except Arabic numerals (Z14494): Description missing
• remove all characters except ASCII alphanumerics (Z10171): keeping [0-9A-Za-z]
• remove all characters not in second string (Z14515): leaves only the characters in string 1 that are also in string 2
• remove all characters in second string (Z14520): leaves only the characters in string 1 that are not in string 2

Duplicates

• remove duplicate characters (Z11102): keeps only first instance of each character
  • remove repeated characters (Z19185): remove repeat occurrences of any character in the string, just leave the first one
• replace multiple spaces with single spaces (Z22507): removes repeated (regular U+0020) spaces in a string, leaving only a single space in place

At the start and end

• remove first and last character (Z26414): removes the first and last character of a string
• unwrap string (Z11151): removes text from start and end of string once only if both are present

At the start (prefix)

• remove first N characters of string (Z14636): return the string with the first N characters removed
  • remove first character (Z14456): removes the first character of a string and returns the rest
• String without prefix (Z31955): if a string begins with the given prefix, removes the prefix, otherwise returns the string unchanged
  • trim Code point from start of String (Z31880): Description missing
• discard from start of first substring (Z11410): if the substring is found in the full string, discard everything after and including the first occurrence, otherwise leave unchanged
• discard from end of first substring (Z11412): if the substring is found in the full string, discard everything after but not including the first occurrence, otherwise leave unchanged
• discard from start of last substring (Z11414): if the substring is found in the full string, discard everything after and including the last occurrence, otherwise leave unchanged
• discard from end of last substring (Z11416): if the substring is found in the full string, discard everything after but not including the last occurrence, otherwise leave unchanged

At the end (suffix)

• remove last character (Z11879): Description missing
• String without suffix (Z11170): if a string ends with the given suffix, remove the suffix, otherwise return the string unchanged
• discard until start of first substring (Z11418): if the substring is found in the full string, discard everything before but not including the first occurrence, otherwise leave unchanged
• discard until end of first substring (Z11420): if the substring is found in the full string, discard everything before and including the first occurrence, otherwise leave unchanged
• discard until start of last substring (Z11422): if the substring is found in the full string, discard everything before but not including the last occurrence, otherwise leave unchanged
• discard until end of last substring (Z11424): if the substring is found in the full string, discard everything before and including the last occurrence, otherwise leave unchanged

Whitespace

• trim string (Z10079): Remove starting and ending whitespaces
  • remove leading spaces (Z10084): Remove all leading spaces in a string
  • Remove trailing spaces (Z10095): Remove all trailing spaces in a string

Concatenation and duplication

• join two strings (Z10000): combine two strings without any separation, one after the other
  • join two strings with space (Z27182): Description missing
  • concatenate many strings (Z21394): Description missing
  • join list of strings with delimiter (Z12899): returns string composed of list elements separated by a given delimiter
  • join list of strings with spaces (Z22504): joins a list of strings inserting a single space between each
  • sentence from list of words (English conventions) (Z22514): takes a list of words, joins with spaces, collapses multiple spaces, remove spaces before punctuation, turns to sentence case and adds a full stop at the end
  • enclose string (Z27385): returns a string preceded by a prefix and followed by a suffix (no separators)
  • Add chars every n chars (Z19654): Broader version of Z19645
  • join two strings with space unless empty (Z36804): If one string is empty, return the other. If both are empty, return empty. Otherwise join the two strings with a space in between.
• duplicate string (Z10753): takes a string and returns it duplicated
  • Replicate string n-times (Z12624): Replicates a string n times: (e.g. f("a",5) -> "aaaaa")
  • duplicate string N times (Z10911): Description missing

Case

• to uppercase (Z10018): Convert a string to uppercase letters
• to lowercase (Z10047): Convert a string to lowercase letters
  • lowercase first letter (Z32953): turns the first letter of the given string into lowercase if it was not already
• to Title Case (Z10251): converts a string to title case
• to PascalCase (Z10290): convert string to Pascal Case
• to camelCase (Z10816): convert string to lower camelCase,
• to snake_case (Z10281): convert string to snake case

Formatting and presentation

• turn to superscript (Z19612): Takes a text, and all characters that have a superscript version are replaced with such.
• pretty " (Z11484): replace " with pretty left-right quotes depending on position
• pretty ' (Z11490): replace ' with pretty left-right quotes depending on position
• wrap in quotes (Z35494): Wraps a text in quote marks, optionally swaps existing quotes with a lower quote level
• format digit strings with commas (Z13473): This lets you show large natural numbers, adding commas to make them more readable. It uses the International English standard of groups of 3 digits.
• pad string with leading characters to specified length (Z14770): add specified characters at the start until the string is of the required length
• string end padding (Z10108): Add string end padding
• capitalise first letter and add full stop (Z22511): turn a string of words into a sentence format, with an initial capital, and a full stop at the end.
• escape HTML (Z31471): replace &, < and > with the respective HTML entities

Other

• C-style string formatting (Z22699): Description missing
• reverse string (Z10012): Inverts the order of the characters in a String (see Z10548 for one with Unicode grapheme support)
• Infix to Postfix (Z13060): converts infix operators and operands to postfix format
• String to codepoint list (Z22717): Converts a string to a list of codepoints. Reverse at Z22693
• split string to list (Z25614): Splits a string to a list of strings based on a separator.
• convert digits to lower indices (subscript) (Z27053): Convert decimal digits to lower indices (subscript). E.g. converts simple chemical formulas (where digits are intended as lower indexes exclusively) in "ASCII" to Unicode.
• enumerate adjacent-key typos for digit string (Z32085): assumes QWERTY layout number row or numpad

Regular expressions

• number of regular expression matches with flags (Z25847): returns the number of substrings matched by the regex
• regular expression match with flags (Z25829): returns a list of strings matched by the regex
  • first regular expression match with flags (Z25833): returns a string first matched by the regex, or an empty string if no match is present
  • nth regular expression match with flags (Z25853): returns the substring corresponding to the nth match of a regex with the target string
• regular expression substitute with flags (Z12316): $N for capture groups. Flags supported should at least be 'i', 'm', and 'g'.
• replace all (regex, case sensitive) (Z10193): replace characters in a string with another string according to a regex pattern
  • replace multiple characters with replacement char (Z29153): Description missing
  • replace nth regex match (Z29890): Description missing

Encode and decode

• string to hex (UTF-8) (Z10366): convert string of UTF-8 characters into hexadecimal
• hex (string) to string (UTF-8) (Z10373): hex to string
• URI percent encode (Z10761): encodes certain characters using URI percent encoding syntax
• URI percent decode (Z10774): decodes a percent-encoded input string
• international morse code encode (Z10944): encodes the supplied string in morse code, separating letter encodings by spaces and words by " / "
• international morse code decode (Z10956): decodes the supplied string in morse code: separate letter encodings by spaces and words by " / "
• encode NATO phonetic alphabet code (Z10309): Encodes a Latin alphabet string using the NATO phonetic alphabet.
• decode NATO phonetic alphabet code (Z10970): case insensitive
• Base16 Encode (Z11003): Encode a string into base16
• Base16 Decode (Z11007): Decode a string from base16
• Base32 encode (Z14189): Description missing
• Base32 decode (Z14195): Decode a string from Base32
• Base64 encode (Z10057): Encode a UTF-8 string into base64.
• Base64 decode (Z10062): Decode a string from base64 (needed to demonstrate base64 encode/decode examples)

Cryptography

Caesar cipher

(alphabet needs to be specified when calling these functions)

• Caesar cipher (Latin alphabet) (Z12812): rotates letters in the Latin alphabet forward by a defined number of places
• ROT1 (Latin alphabet) (Z10846): move by one letter in the English alphabet
• ROT13 (Latin alphabet) (Z10627): encode or decode a Latin alphabet string using the ROT13 cipher ROT13 encrypt/decrypt
• ROT25 (Latin alphabet) (Z10851): move each letter one letter back in the English alphabet
• Caesar cipher (Bengali alphabets) (Z17530): Description missing
• Caesar cipher (Bengali Consonants) (Z17526): Description missing
• caesar cipher (Dagbani alphabet) (Z20669): Description missing
• encrypt Caesar (custom alphabet) (Z23869): Encrypt using Caesar's cipher with a custom alphabet. Characters not in the alphabet will not be encrypted.

Substitution ciphers

• to Scream Cipher (Z22725): Based on xkcd.com/3054 - reverse at Z22728
• from Scream Cipher (Z22728): Based on xkcd.com/3054 - reverse at Z22725

Vigenère cipher

• Vigenère cipher (Z23848): Encrypt with Vigenère cipher. Characters not in the alphabet will not be encoded.
• decrypt Vigenère (Z23851): Decrypts a text encrypted with Vigenère code. Ignores characters not in the alphabet.
• encrypt Vigenère (alphabet as list) (Z23953): Encrypt using Vigenère code with alphabet given as a list of letters.
• decrypt Vigenère (alphabet as list) (Z23956): Decrypt using Vigenère code with alphabet given as a list of letters.

Cryptographic hash functions

(would be better with types representing a stream of bytes)

• SHA-1 (Z10148): SHA-1 hash of the UTF-8 representation of a string, as a lowercase hexadecimal byte string SHA-1
• SHA-256 (Z10124): returns the hexadecimal hash of a string in SHA-256 SHA-256
• SHA-384 (Z10132): returns the hexadecimal hash of a string in SHA-384 SHA-384
• SHA-512 (Z10067): hash a string using the SHA-512 function SHA-512

Wikitext and Mediawiki string operations

• italicise in Wikitext (Z11019): wrap string with two pairs of single quotes (ABC -> ABC). Careful using this if your text has special formatting characters.
• bold in Wikitext (Z11139): bold a string by triple quoting, e.g. (ABC -> ABC). Careful if there are special characters.
• csv record to wikitable row (Z10919): Converts a validly formatted (RFC 4180) comma-separated value series into the contents of a valid wikitable row (not including the row start or row end characters) where variables are separated by '||', and any whitespace is unchanged. Be careful to validly render CSV with quoted fields and with pipes ('|') in the field.
• wrap with XML tag (Z11156): adds <tag> and </tag> around a string
• substitute mediawiki editchangetags query (Z17954): 36621225 ... ↓ ?action=editchangetags&ids%5B36621225%5D=1 ... &ids
• substitute mediawiki revisiondelete query (Z17956): 36621225 ... ↓ ?action=revisiondelete&ids%5B36621225%5D=1 ... &ids

Comma-separated values (CSV)

• string is element of CSV (Z11094): tests whether a string is an element of a validly formatted (RFC 4180) comma-separated value series (single row, not whole file); be careful to validly interpret a CSV with quoted fields

Color operations

Only includes functions that operate on hex triplets. For other color functions, see Wikifunctions:Catalogue/Color functions.

• mix colours (string) (Z12997): Calculates the midpoint between two colours. It prefers input in hexadecimal but also accepts basic colour names.
• convert hex colour to HSL, HSV, RGB, CMYK (Z13017): converts a hexadecimal colour code into HSL, HSV, RGB, and CMYK formats
• convert hex colour to [R,G,B] (Z17664): output is a list of three natural numbers, each between 0 and 255
• convert [R,G,B] to hex colour (Z17687): input is triplets of natural numbers between 0 and 255. output is lowercase preceded by #
• convert X11 color to hex (Z17713): converts color names to hex (including leading #) https://www.w3.org/TR/css-color-3/#svg-color
• opposite colour (Z13023): in the RGB colour space
• colour contrast ratio (Z13028): returns colour contrast ratio 'X:1' for given hex colours
• tint of color (Z18184): Mix a color with white by a given percentage
• Shade of colour (Z18189): Returns the shade of a colour by mixing it with a percentage of black.
• Tone of colour (Z18196): Returns the tone of a colour by mixing it with gray
• Analogous colour (Z18204): Returns the colours which are 30 degrees apart from the input base colour.
• Tetradic colours (square) (Z18208): Returns colours that are 90 degrees apart from the input base colour.
• Triadic colours (Z18212): Returns the input plus the two colours that are 120 degrees and 240 degrees apart from the input base colour.
• Saturation of colour (Z18263): Returns the intensity of a colour. 100% saturation means there is no addition of gray.
• Lightness of colour (Z18268): Returns the measure of how light or dark a colour is, with 0% being completely black and 100% being completely white
• Subtractive color (Z18296): Subtract the second colour from the first color.
• Additive colours (Z18300): Additively mix two hex colours using the RGB model.

HTML fragments

See Wikifunctions:Catalogue/HTML operations