Comparison of programming languages (string functions)

Programming language comparisons
General comparison
Basic syntax
Basic instructions
Arrays
Associative arrays
String operations
String functions
List comprehension
Object-oriented programming
Object-oriented constructors
Database access
Database RDBMS

Evaluation strategy
List of "hello world" programs

ALGOL 58's influence on ALGOL 60
ALGOL 60: Comparisons with other languages
Comparison of ALGOL 68 and C++
ALGOL 68: Comparisons with other languages
Compatibility of C and C++
Comparison of Pascal and Borland Delphi
Comparison of Object Pascal and C
Comparison of Pascal and C
Comparison of Java and C++
Comparison of C# and Java
Comparison of C# and Visual Basic .NET
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String functions are used in computer programming languages to manipulate a string or query information about a string (some do both).

Most computer programming languages that have a string datatype will have some string functions although there may be other low level ways within each language to handle strings directly. In object oriented languages, string functions are often implemented as properties and methods of string objects. In functional and list based languages a string is represented as a list (of character codes), therefore all list-manipulation procedures could be considered string functions. However such languages may implement a subset of explicit string-specific functions as well.

The most basic example of a string function is the length(string) function. This function returns the length of a string literal.

eg. length("hello world") would return 11.

Other languages may have string functions with similar or exactly the same syntax or parameters or outcomes. For example in many languages the length function is usually represented as len(string). The below list of common functions aims to help limit this confusion.

Contents

Common string functions (multi language reference)

Here is a list of common string functions which are found in other languages. Any other equivalent functions used by other languages are also listed. The below list of common functions aims to help programmers find the equivalent function in a language. Note, string concatenation and regular expressions are handled in separate pages. Statements in guillemets (« … ») are optional.

CharAt

Definition charAt(string,integer) returns character.
Description Returns character at index in the string.
Equivalent See substring of length 1 character.
Format Languages Base index
string[i] ALGOL 68, Pascal, Object Pascal (Delphi) 1
string[i] C, C++, C#, D, FreeBASIC, Go, Python1, PHP, Ruby1, Windows PowerShell 0
string{i} PHP (deprecated in 5.3) 0
string(i) Ada ≥1
Mid(string,i,1) VB 1
string.Chars(i) VB.NET 0
string(i:i) Fortran 1
string.charAt(i) Java, JavaScript 0
string.[i] OCaml, F# 0
String.sub (string, i) Standard ML 0
string !! i Haskell 0
(string-ref string i) Scheme 0
(char string i) Common Lisp 0
substr(string, i, 1) Perl1 0
string.at(i) C++ (std::string only) (w/ bounds checking) 0
lists:nth(i, string) Erlang 1
[string characterAtIndex:i] Objective-C (NSString * only) 0
string.sub(string, i, i)
(string):sub(i, i)
Lua1 1
string at: i Smalltalk (w/ bounds checking) 1
string index string i Tcl 0
  1. In this language, the index can be negative, which then indicates the number of places before the end of the string.
{ Example in Pascal }
var 
  MyStr: string = 'Hello, World';
  MyChar: Char;
begin
  MyChar := MyStr[2];         // 'e'
# Example in ALGOL 68 #
"Hello, World"[2];         // 'e'
// Example in C#
"Hello, World"[2];         // 'l'
# Examples in Python
"Hello, World"[2]          #  'l'
"Hello, World"[-3]         #  'r'
' Example in Visual Basic
GetChar("Hello, World", 2) '  "e"
' Example in Visual Basic .NET
"Hello, World".Chars(2)    '  "l"c
" Example in Smalltalk"
'Hello, World' at: 2.    "$e"

Compare (integer result)

Definition compare(string1,string2) returns integer.
Description Compares two strings to each other. If they are equivalent, a zero is returned. Otherwise, most of these routines will return a positive or negative result corresponding to whether string1 is lexicographically greater than, or less than, respectively, than string2. The exceptions are the Scheme and REXX routines which return the index of the first mismatch.
Format Languages

IF string1<string2 THEN -1 ELSE ABS (string1>string2) FI

ALGOL 68
cmp(string1, string2) Python (before 3.0 only)
int(string1 > string2) - int(string1 < string2) Python (since 3.0)
strcmp(string1, string2) C, C++ (char * only), PHP
std.string.cmp(string1, string2) D
StrComp(string1, string2) VB, Object Pascal (Delphi)
string1 cmp string2 Perl
string1 <=> string2 Ruby
string1.compare(string2) C++ (std::string only)
compare(string1, string2) REXX
CompareStr(string1, string2) Pascal, Object Pascal (Delphi)
string1.compareTo(string2) Java
string1.CompareTo(string2) VB .NET, C#, F#
(string= string1 string2) Common Lisp
(string-compare string1 string2 p< p= p>) Scheme (SRFI 13)
compare string1 string2 OCaml
String.compare (string1, string2) Standard ML (returns LESS, EQUAL, or GREATER)
compare string1 string2 Haskell (returns LT, EQ, or GT)
[string]::Compare(string1, string2) Windows PowerShell
[string1 compare:string2] Objective-C (NSString * only)
LLT(string1,string2)
LLE(string1,string2)
LGT(string1,string2)
LGE(string1,string2)
Fortran (returns .TRUE. or .FALSE.)
string1.localeCompare(string2) JavaScript
bytes.Compare([]byte(string1), []byte(string2)) Go
string compare ?-nocase? ?-length int? string1 string2 Tcl


# Example in Python
cmp("hello", "world")      # returns -1
/** Example in REXX */ 
compare("hello", "world")  /* returns index of mismatch: 1 */
; Example in Scheme
(use-modules (srfi srfi-13))
; returns index of mismatch: 0
(string-compare "hello" "world" values values values)

Compare (relational operator-based, Boolean result)

Definition string1 op string2 OR (compare string1 string2) returns Boolean.
Description Lexicographically compares two strings using a relational operator or function. Boolean result returned.
Format Languages
string1 op string2, where op can be any of =, <>, <, >, <= and >= Pascal, Object Pascal (Delphi), OCaml, Standard ML, VB, VB .NET, F#
string1 op string2, where op can be any of =, /=, ≠, <, >, <=, ≤ and ≥; Also: EQ, NE, LT, LE, GE and GT ALGOL 68
(stringX? string1 string2), where X can be any of =, -ci=, <, -ci<, >, -ci>, <=, -ci<=, >= and -ci>= (operators starting with '-ci' are case-insensitive) Scheme
(stringX string1 string2), where X can be any of =, -ci=, <>, -ci<>, <, -ci<, >, -ci>, <=, -ci<=, >= and -ci>= (operators starting with '-ci' are case-insensitive) Scheme (SRFI 13)
(stringX string1 string2), where X can be any of =, -equal, /=, -not-equal, <, -lessp, >, -greaterp, <=, -not-greaterp, >= and -not-lessp (the verbal operators are case-insensitive) Common Lisp
string1 op string2, where op can be any of =, \=, <, >, <= and >= REXX
string1 op string2, where op can be any of =, /=, <, >, <= and >= Ada
string1 op string2, where op can be any of ==, /=, <, >, =< and >= Erlang
string1 op string2, where op can be any of ==, /=, <, >, <= and >= Haskell
string1 op string2, where op can be any of eq, ne, lt, gt, le and ge Perl
string1 op string2, where op can be any of ==, !=, <, >, <= and >= C++ (std::string only), C#, D, Go, JavaScript, Python, PHP, Ruby
string1 op string2, where op can be any of -eq, -ceq, -ne, -cne, -lt, -clt, -gt, -cgt, -le, -cle, -ge, and -cge (operators starting with 'c' are case-sensitive) Windows PowerShell
string1 op string2, where op can be any of ==, ~=, <, >, <= and >= Lua
string1 op string2, where op can be any of =, ~=, <, >, <= and >= Smalltalk
string1 op string2, where op can be any of ==, /=, <, >, <= and >=; Also: .EQ., .NE., .LT., .LE., .GT. and .GE. Fortran
% Example in Erlang
"hello" > "world".            % returns false
# Example in Windows PowerShell
"hello" -gt "world"           # returns false
;; Example in common lisp
(string> "art" "painting")      ; returns nil
(string< "art" "painting")      ; returns non nil

Concatenation

Definition concatenate(string1,string2) returns string.
Description Concatenates (joins) two strings to each other, returning the combined string. Note that some languages like C have mutable strings, so really the second string is being appended to the first string and the mutated string is returned.
Format Languages
string1 & string2 Ada, FreeBASIC, VB, VB .NET
strcat(string1, string2) C, C++ (char * only; modifies string1, which must have enough space to store the result)
string1 . string2 Perl, PHP
string1 + string2 ALGOL 68, C++ (std::string only), C#, FreeBASIC, Go, Pascal, Object Pascal (Delphi), Java, JavaScript, Windows PowerShell, Python, Ruby, F#, Turing, VB
string1 ~ string2 D
(string-append string1 string2) Scheme
(concatenate 'string string1 string2) Common Lisp
string1 || string2 REXX, SQL
string1 // string2 Fortran
string1 ++ string2 Erlang, Haskell
string1 ^ string2 OCaml, Standard ML, F#
[string1 stringByAppendingString:string2] Objective-C (NSString * only)
string1 .. string2 Lua
string1 , string2 Smalltalk
string1 string2 SNOBOL
{ Example in Pascal }
'abc' + 'def';      // returns "abcdef"
// Example in C#
"abc" + "def";      // returns "abcdef"
' Example in Visual Basic
"abc" & "def"       '  returns "abcdef"
"abc" + "def"       '  returns "abcdef"
"abc" & Null        '  returns "abc"
"abc" + Null        '  returns Null
// Example in D
"abc" ~ "def";      // returns "abcdef"
;; Example in common lisp
(concatenate 'string "abc " "def " "ghi")  ; returns "abc def ghi"

Contains

Definition contains(string,substring) returns boolean
Description Returns whether string contains substring as a substring. This is equivalent to using #Find and then detecting that it does not result in the failure condition listed in the third column of the #Find section. However, some languages have a simpler way of expressing this test.
Related
Format Languages
string_in_string(string, loc int, substring) ALGOL 68
ContainsStr(string, substring) Object Pascal (Delphi)
string.Contains(substring) C#, VB .NET, Windows PowerShell, F#
string.contains(substring) Java (1.5+)
string.indexOf(substring) >= 0 JavaScript
strpos(string, substring) !== false PHP
substring in string Python (2.3+)
string.find(string, substring) ~= nil Lua
string.include?(substring) Ruby
Data.List.isInfixOf substring string Haskell (GHC 6.6+)
string includesSubString: substring Smalltalk (Squeak, Pharo)
String.isSubstring substring string Standard ML
(search substring string) Common Lisp
¢ Example in ALGOL 68 ¢
string in string("e", loc int, "Hello mate");      ¢ returns true ¢
string in string("z", loc int, "word");            ¢ returns false ¢
// Example In C#
"Hello mate".Contains("e");      // returns true
"word".Contains("z");            // returns false
#  Example in Python
"e" in "Hello mate"              #  returns true
"z" in "word"                    #  returns false

Equality

Tests if two strings are equal. See also #Compare and #Compare. Note that doing equality checks via. a generic Compare with integer result is not only confusing for the programmer but is often a significantly more expensive operation, this is especially true when using "C-strings".

Format Languages
string1 == string2 Python, C++(std::string only), C# Go, JavaScript (similarity), PHP (similarity), Ruby, Erlang, Haskell, Lua, D
string1 === string2 JavaScript, PHP
string1 == string2 or
string1 .EQ. string2
Fortran
strcmp(string1, string2) == 0 C, C++ (char * only)
(string=? string1 string2) Scheme
(string= string1 string2) Common Lisp
string1 = string2 ALGOL 68, Ada, Object Pascal (Delphi), OCaml, Pascal, REXX, Standard ML, VB, VB .NET, F#, Smalltalk
test string1 = string2, or
[ string1 = string2 ]
Bourne Shell
string1 eq string2 Perl
string1.equals(string2) Java
string1 -eq string2, or
[string]::Equals(string1, string2)
Windows PowerShell
[string1 isEqualToString:string2], or
[string1 isEqual:string2]
Objective-C (NSString * only)
// Example in C#
"hello" == "world"           // returns false
' Example in Visual Basic
"hello" = "world"            '  returns false
# Example in Windows PowerShell
"hello" -eq "world"          #  returns false

Find

Definition find(string,substring) returns integer
Description Returns the position of the start of the first occurrence of substring in string. If the substring is not found most of these routines return an invalid index value – -1 where indexes are 0-based, 0 where they are 1-based – or some value to be interpreted as Boolean FALSE.
Related instrrev
Format Languages If not found
string in string(substring, pos, string[startpos:]) ALGOL 68 returns BOOL: TRUE or FALSE, and position in REF INT pos.
InStr(«startposstring,substring) VB (positions start at 1) returns 0
index(string,substring) AWK returns 0
index(string,substring«,startpos») Perl returns -1
instr(«startposstring,substring) FreeBASIC returns 0
strpos(string,substring«,startpos») PHP returns FALSE
locate(string, substring) Ingres returns string length + 1
strstr(string, substring) C, C++ (char * only, returns pointer to first character) returns NULL
std.string.find(string, substring) D returns -1
strings.Index(string, substring) Go returns -1
pos(substring, string) Pascal, Object Pascal (Delphi) returns 0
pos(substring, string«,startpos») REXX returns 0
string.find(substring«,startpos») C++ (std::string only) returns std::string::npos
string.find(substring«,startpos«,endpos»») Python returns -1
string.index(substring«,startpos«,endpos»») raises ValueError
string.index(substring«,startpos») Ruby returns nil
string.indexOf(substring«,startpos») Java, JavaScript returns -1
string.IndexOf(substring«,startpos«, charcount»») VB .NET, C#, Windows PowerShell, F# returns -1
string:str(string, substring) Erlang returns 0
(string-contains string substring) Scheme (SRFI 13) returns #f
(search substring string) Common Lisp returns NIL
List.findIndex (List.isPrefixOf substring) (List.tails string) Haskell (returns Just index) returns Nothing
Str.search_forward (Str.regexp_string substring) string 0 OCaml raises Not_found
Substring.size (#1 (Substring.position substring (Substring.full string))) Standard ML returns string length
[string rangeOfString:substring].location Objective-C (NSString * only) returns NSNotFound
string.find(string, substring)
(string):find(substring)
Lua returns nil
string indexOfSubCollection: substring startingAt: startpos ifAbsent: aBlock
string findString: substring startingAt: startpos
Smalltalk (Squeak, Pharo) evaluate aBlock which is a block closure (or any object understanding value)
returns 0
startpos = INDEX(string, substring «,back» «, kind») Fortran returns 0 if substring is not in string; returns LEN(string)+1 if substring is empty
POSITION(substring IN string) SQL returns 0 (positions start at 1)
; Examples in Common Lisp
(search "e" "Hello mate")             ;  returns 1
(search "z" "word")                   ;  returns NIL
// Examples in C#
"Hello mate".IndexOf("e");            // returns 1
"Hello mate".IndexOf("e", 4);         // returns 9
"word".IndexOf("z");                  // returns -1
; Examples in Scheme
(use-modules (srfi srfi-13))
(string-contains "Hello mate" "e")    ;  returns 1
(string-contains "word" "z")          ;  returns #f
' Examples in Visual Basic
InStr("Hello mate", "e")              '  returns 2
InStr(5, "Hello mate", "e")           '  returns 10
InStr("word", "z")                    '  returns 0

Find character

Definition find character(string,char) returns integer
Description Returns the position of the start of the first occurrence of the character char in string. If the character is not found most of these routines return an invalid index value – -1 where indexes are 0-based, 0 where they are 1-based – or some value to be interpreted as Boolean FALSE. This can be accomplished as a special case of #Find, with a string of one character; but it may be simpler or more efficient in many languages to locate just one character. Also, in many languages, characters and strings are different types, so it is convenient to have such a function.
Related find
Format Languages If not found
char in string(char, pos, string[startpos:]) ALGOL 68 returns BOOL: TRUE or FALSE, and position in REF INT pos.
instr(string, any char«,startpos») (char, can contain more them one char, in witch case the position of the first appearence of any of them is returned.) FreeBASIC returns 0
strchr(string,char) C, C++ (char * only, returns pointer to character) returns NULL
std.string.find(string, dchar) D returns -1
string.find(char«,startpos») C++ (std::string only) returns std::string::npos
strings.IndexRune(string,char) Go returns -1
string.indexOf(char«,startpos») Java returns -1
string.IndexOf(char«,startpos«, charcount»») VB .NET, C#, Windows PowerShell, F# returns -1
(position char string) Common Lisp returns NIL
List.elemIndex char string Haskell (returns Just index) returns Nothing
String.index string char OCaml raises Not_found
position = SCAN (string, set «, back» «, kind») or
position = VERIFY (string, set «, back» «, kind»)[a]
Fortran returns zero
string indexOf: char ifAbsent: aBlock
string indexOf: char
string includes: char
Smalltalk evaluate aBlock which is a BlockClosure (or any object understanding value)
returns 0
returns true or false
// Examples in C#
"Hello mate".IndexOf('e');              // returns 1
"word".IndexOf('z')                     // returns -1
; Examples in Common Lisp
(position #\e "Hello mate")             ;  returns 1
(position #\z "word")                   ;  returns NIL

^a Given a set of characters, SCAN returns the position of the first character found,[1] while VERIFY returns the position of the first character that does not belong to the set.[2]

Format

Definition format(formatstring, items) returns string
Description Returns the formatted string representation of one or more items. See sprintf for more information.
Format Languages
associate(file, string); putf(file, $formatstring$, items) ALGOL 68
Format(item, formatstring) VB
sprintf(formatstring, items) Perl, PHP, Ruby
io_lib:format(formatstring, items) Erlang
sprintf(outputstring, formatstring, items) C, C++ (char * only)
std.string.format(formatstring, items) D
Format(formatstring, items) Object Pascal (Delphi)
fmt.Sprintf(formatstring, items) Go
printf -v outputstring formatstring items Bash shell
formatstring % (items) Python, Ruby
formatstring.format(items) Python 3.x (format specification is different from printf)
Printf.sprintf formatstring items OCaml (formatstring must be a fixed literal at compile time for it to have the correct type), F#
Text.Printf.printf formatstring items Haskell (GHC)
String.format(formatstring, items) Java
String.Format(formatstring, items) VB .NET, C#, F#
(format formatstring items) Scheme (SRFI 28)
(format nil formatstring items) Common Lisp
formatstring -f items Windows PowerShell
[NSString stringWithFormat:formatstring, items] Objective-C (NSString * only)
string.format(formatstring, items)
(formatstring):format(items)
Lua
WRITE (outputstring, formatstring) items Fortran
// Example in C#
String.Format("My {0} costs {1:C2}", "pen", 19.99); // returns "My pen costs $19.99"
// Example in Object Pascal (Delphi)
Format('My %s costs $%2f', ['pen', 19.99]);         // returns "My pen costs $19.99"
// Example in Java
String.format("My %s costs $%2f", "pen", 19.99);    // returns "My pen costs $19.99"
# Example in Python
"My %s costs $%.2f" % ("pen", 19.99);                #  returns "My pen costs $19.99"
"My {0} costs ${1:.2f}".format("pen", 19.99);        #  returns "My pen costs $19.99"
; Example in Scheme
(format "My ~a costs $~1,2F" "pen" 19.99)           ;  returns "My pen costs $19.99"

Inequality

Tests if two strings are not equal. See also #Equality.

Format Languages
string1 ne string2, or string1 NE string2 ALGOL 68 - note: the operator "ne" is literally in bold type-font.
string1 /= string2 ALGOL 68, Ada, Erlang, Fortran, Haskell
string1 <> string2 VB, VB .NET, Pascal, Object Pascal (Delphi), OCaml, PHP, Standard ML, F#
string1 ne string2 Perl
(string<> string1 string2) Scheme (SRFI 13)
(string/= string1 string2) Common Lisp
string1 != string2 C++ (std::string only), C#, Go, JavaScript (not similar), PHP (not similar), Python, Ruby, D
string1 !== string2 JavaScript, PHP
string1 \= string2 REXX
test string1 != string2, or
[ string1 != string2 ]
Bourne Shell
string1 -ne string2, or
-not [string]::Equals(string1, string2)
Windows PowerShell
string1 ~= string2 Lua, Smalltalk
// Example in C#
"hello" != "world"    // returns true
' Example in Visual Basic
"hello" <> "world"    '  returns true
# Example in Windows PowerShell
"hello" -ne "world"   #  returns true

index

see #Find

indexof

see #Find

instr

see #Find

instrrev

see #rfind

join

Definition join(separator, list_of_strings) joins a list of strings with a separator
Description Joins the list of strings into a new string, with the separator string between each of the substrings. Opposite of split.
Related sprintf
Format Languages
std.string.join(array_of_strings, separator) D
string:join(list_of_strings, separator) Erlang
join(separator, list_of_strings) Perl, PHP
implode(separator, array_of_strings) PHP
separator.join(sequence_of_strings) Python
array_of_strings.join(separator) Ruby, JavaScript
(string-join array_of_strings separator) Scheme (SRFI 13)
(format nil "~{~a~^separator~}" array_of_strings) Common Lisp
strings.Join(array_of_strings, separator) Go
String.concat separator list_of_strings OCaml
String.concatWith separator list_of_strings Standard ML
Data.List.intercalate separator list_of_strings Haskell (GHC 6.8+)
Join(array_of_strings, separator) VB
String.Join(separator, array_of_strings) VB .NET, C#, F#
&{$OFS=$separator; "$array_of_strings"}, or
array_of_strings -join separator
Windows PowerShell
[array_of_strings componentsJoinedByString:separator] Objective-C (NSString * only)
table.concat(table_of_strings, separator) Lua
String streamContents: [ :stream | collectionOfAnything asStringOn: stream delimiter: separator ] Smalltalk (Squeak, Pharo)
// Example in C#
String.Join("-", {"a", "b", "c"})  // "a-b-c"
# Example in Perl
join( '-', ('a', 'b', 'c'));       # 'a-b-c'
# Example in Python
"-".join(["a", "b", "c"])          #  'a-b-c'
# Example in Ruby
["a", "b", "c"].join("-")          #  'a-b-c'
; Example in Scheme
(use-modules (srfi srfi-13))
(string-join '("a" "b" "c") "-")   ;  "a-b-c"

lastindexof

see #rfind

left

Definition left(string,n) returns string
Description Returns the left n part of a string. If n is greater than the length of the string then most implementations return the whole string (exceptions exist - see code examples).
Format Languages
string (string'First .. string'First + n - 1) Ada
string:substr(string, start, length) Erlang
Left(string,n) VB
left(string,n) FreeBASIC, Ingres
left(string,n «,padchar») REXX, Erlang
substr(string, 0, n) AWK (changes string), Perl, PHP
string[:n] Python
string[0, n]
string[0..n - 1]
Ruby
string.substr(0,n) C++ (std::string only)
string[0 .. n] D (if n is larger than the length of the string, then in Debug mode ArrayRangeException is thrown, in Release mode, the behaviour is unspecified)
string.Substring(0,n) VB .NET, C#, Windows PowerShell, F#
leftstr(string, n) Pascal, Object Pascal (Delphi)
string.substring(0,n) Java, JavaScript
(string-take string n) Scheme (SRFI 13)
take n string Haskell
[string substringToIndex:n] Objective-C (NSString * only)
String.extract (string, n, NONE) Standard ML
String.sub string 0 n OCaml (if n is larger than length of string, raises Invalid_argument)
string.[..n] F#
string.sub(string, 1, n)
(string):sub(1, n)
Lua
string first: n Smalltalk (Squeak, Pharo)
string(:n) Fortran
/* Examples in REXX */
left("abcde", 3)         /* returns "abc"      */
left("abcde", 8)         /* returns "abcde   " */
left("abcde", 8, "*")    /* returns "abcde***" */
; Examples in Scheme
(use-modules (srfi srfi-13))
(string-take "abcde", 3) ;  returns "abc" 
(string-take "abcde", 8) ;  error
' Examples in Visual Basic
Left("sandroguidi", 3)   '  returns "san" 
Left("sandroguidi", 100) '  returns "sandroguidi"

len

see #length


length

Definition length(string) returns an integer number
Description Returns the length of a string (not counting the null terminator or any other of the string's internal structural information). An empty string returns a length of 0.
Format Returns Languages
string'Length Ada
UPB string ALGOL 68
length(string) FreeBASIC, Ingres, Perl, Pascal, Object Pascal (Delphi), REXX, SQL
len(string) Python, Go
length(string), string:len(string) Erlang
Len(string) VB
string.Length Number of 16-bit UTF-16-encoded blocks VB .NET, C#, Windows PowerShell, F#
string.size OR string.length Number of bytes (Ruby lacks Unicode support) Ruby
strlen(string) Number of bytes C, C++ (char * only), PHP
string.length() C++ (std::string only)
string.length D
string.length() Number of 16-bit UTF-16-encoded blocks Java
string.length JavaScript
(string-length string) Scheme
(length string) Common Lisp
String.length string OCaml
size string Standard ML
length string Number of Unicode codepoints Haskell
[string length] Objective-C (NSString * only)
string.len(string)
(string):len()
#string
Lua
string size Smalltalk
LEN(string), or LEN_TRIM(string) Fortran
// Examples in C#
"hello".Length;      // returns 5
"".Length;           // returns 0
# Examples in Erlang
string:len("hello"). %  returns 5
string:len("").      %  returns 0
# Examples in Perl
length("hello");     #  returns 5
length("");          #  returns 0
' Examples in Visual Basic
Len("hello")         '  returns 5
Len("")              '  returns 0
//Examples in Objective-C
[@"hello" Length]   //returns 5
[@"" Length]   //returns 0
-- Examples in Lua
("hello"):len() -- returns 5
#"" -- returns 0

locate

see #Find


Lowercase

Definition lowercase(string) returns string
Description Returns the string in lower case.
Format Languages
LCase(string) VB
lcase(string) FreeBASIC
lc(string) Perl
tolower(char) C (operates on one character)
std.string.tolower(string) D
transform(string.begin(), string.end(), result.begin(), tolower)[3] C++ (std::string only, result is stored in string result which is at least as long as string, and may or may not be string itself)
lowercase(string) Object Pascal (Delphi)
strtolower(string) PHP
echo "string" | tr 'A-Z' 'a-z' Unix
string.lower() Python
string.downcase Ruby (only ASCII characters as Ruby lacks Unicode support)
strings.ToLower(string) Go
(string-downcase string) Scheme (R6RS), Common Lisp
String.lowercase string OCaml
String.map Char.toLower string Standard ML
map Char.toLower string Haskell
string.toLowerCase() Java, JavaScript
to_lower(string) Erlang
string.ToLower() VB .NET, C#, Windows PowerShell, F#
[string lowercaseString] Objective-C (NSString * only)
string.lower(string)
(string):lower()
Lua
string asLowercase Smalltalk
LOWER(string) SQL
// Example in C#
"Wiki means fast?".ToLower();        // "wiki means fast?"
; Example in Scheme
(use-modules (srfi srfi-13))
(string-downcase "Wiki means fast?") ;  "wiki means fast?"
/* Example in C */
#include <ctype.h>
#include <stdio.h>
int main(void) {
    char string[] = "Wiki means fast?";
    int i;
    for (i = 0; i < sizeof(string) - 1; ++i) {
        /* transform characters in place, one by one */ 
        string[i] = tolower(string[i]);
    }
    puts(string);                       /* "wiki means fast?" */
    return 0;
}

mid

see #substring


partition

Definition <string>.partition(separator) returns the sub-string before the separator; the separator; then the sub-string after the separator.
Description Splits the given string by the separator and returns the three substrings that together make the original.
Format Languages
string.partition(separator) Python, Ruby(1.9+)
lists:partition(pred, string) Erlang
split /(separator)/, string, 2 Perl
# Examples in Python
"Spam eggs spam spam and ham".partition('spam')   # ('Spam eggs ', 'spam', ' spam and ham')
"Spam eggs spam spam and ham".partition('X')      # ('Spam eggs spam spam and ham', "", "")
# Examples in Perl
split /(spam)/'Spam eggs spam spam and ham',2;   # ('Spam eggs ', 'spam', ' spam and ham');
split /(X)/'Spam eggs spam spam and ham',2;      # ('Spam eggs spam spam and ham');


replace

Definition replace(string, find, replace) returns string
Description Returns a string with find occurrences changed to replace.
Format Languages
changestr(find, string, replace) REXX
std.string.replace(string, find, replace) D
Replace(string, find, replace) VB
string.Replace(find, replace) VB .NET, C#, F#
str_replace(find, replace, string) PHP
re:replace(string, find, replace, «{return, list}») Erlang
string.replace(find, replace) Python, Java (1.5+)
string.replaceAll(find_regex, replace)[4] Java
string.gsub(find, replace) Ruby
string =~ s/find_regex/replace/g[4] Perl
string.replace(find, replace, "g") or
string.replace(/find_regex/g, replace)[4]
JavaScript
echo "string" | sed 's/find_regex/replace/g'[4] Unix
string.replace(find, replace), or
string -replace find_regex, replace[4]
Windows PowerShell
Str.global_replace (Str.regexp_string find) replace string OCaml
[string stringByReplacingOccurrencesOfString:find withString:replace] Objective-C (NSString * only)
string.gsub(string, find, replace)
(string):gsub(find, replace)
Lua
string copyReplaceAll: find with: replace Smalltalk (Squeak, Pharo)
string map {find replace} string Tcl
// Examples in C#
"effffff".Replace("f", "jump");     // returns "ejumpjumpjumpjumpjumpjump"
"blah".Replace("z", "y");           // returns "blah"
// Examples in Java
"effffff".replace("f", "jump");     // returns "ejumpjumpjumpjumpjumpjump"
"effffff".replaceAll("f*", "jump"); // returns "ejump"
' Examples in Visual Basic
Replace("effffff", "f", "jump")     '  returns "ejumpjumpjumpjumpjumpjump"
Replace("blah", "z", "y")           '  returns "blah"
# Examples in Windows PowerShell
"effffff" -replace "f", "jump"      #  returns "ejumpjumpjumpjumpjumpjump"
"effffff" -replace "f*", "jump"     #  returns "ejump"

reverse

Definition reverse(string)
Description Reverses the order of the characters in the string.
Format Languages
reverse string Perl, Haskell
lists:reverse(string) Erlang
strrev(string) PHP
string[::-1] Python
(string-reverse string) Scheme (SRFI 13)
(reverse string) Common Lisp
string.reverse Ruby
new StringBuilder(string).reverse().toString() Java
std::reverse(string.begin(), string.end()); C++ (std::string only, modifies string)
StrReverse(string) VB
string.Reverse().ToString() VB .NET, C#
implode (rev (explode string)) Standard ML
string.split("").reverse().join("") JavaScript
string.reverse(string)
(string):reverse()
Lua
string reverse Smalltalk
# Example in Perl
reverse "hello"              # returns "olleh"
# Example in Python
"hello"[::-1]                # returns "olleh"
; Example in Scheme
(use-modules (srfi srfi-13))
(string-reverse "hello")     ; returns "olleh"

rfind

Definition rfind(string,substring) returns integer
Description Returns the position of the start of the last occurrence of substring in string. If the substring is not found most of these routines return an invalid index value – -1 where indexes are 0-based, 0 where they are 1-based – or some value to be interpreted as Boolean FALSE.
Related instr
Format Languages If not found
InStrRev(«startposstring,substring) VB returns 0
instrrev(«startposstring,substring) FreeBASIC returns 0
rindex(string,substring«,startpos») Perl returns -1
strrpos(string,substring«,startpos») PHP returns FALSE
string.rfind(substring«,startpos») C++ (std::string only) returns std::string::npos
std.string.rfind(string, substring) D returns -1
string.rfind(substring«,startpos«, endpos»») Python returns -1
string.rindex(substring«,startpos») Ruby returns nil
strings.LastIndex(string, substring) Go returns -1
string.lastIndexOf(substring«,startpos») Java, JavaScript returns -1
string.LastIndexOf(substring«,startpos«, charcount»») VB .NET, C#, Windows PowerShell, F# returns -1
(search substring string :from-end t) Common Lisp returns NIL
[string rangeOfString:substring options:NSBackwardsSearch].location Objective-C (NSString * only) returns NSNotFound
Str.search_backward (Str.regexp_string substring) string (Str.length string - 1) OCaml raises Not_found
string.match(string, '.*()'..substring)
string:match('.*()'..substring)
Lua returns nil
; Examples in Common Lisp
(search "e" "Hello mate" :from-end t)     ;  returns 9
(search "z" "word" :from-end t)           ;  returns NIL
// Examples in C#
"Hello mate".LastIndexOf("e");           // returns 9
"Hello mate".LastIndexOf("e", 4);        // returns 1
"word".LastIndexOf("z");                 // returns -1
' Examples in Visual Basic
InStrRev("Hello mate", "e")              '  returns 10
InStrRev(5, "Hello mate", "e")           '  returns 2
InStrRev("word", "z")                    '  returns 0


right

Definition right(string,n) returns string
Description Returns the right n part of a string. If n is greater than the length of the string then most implementations return the whole string (exceptions exist - see code examples).
Format Languages
string (string'Last - n + 1 .. string'Last) Ada
Right(string,n) VB
right(string,n) FreeBASIC, Ingres
string.substring(string.length()-n) Java
string.substring(string.length-n, string.length) JavaScript
right(string,n «,padchar») REXX, Erlang
substr(string,-n) Perl, PHP
string[-n:] Python
(string-take-right string n) Scheme (SRFI 13)
string[-n..-1] Ruby
string[$-n .. $] D (if n is larger than length of string, then in Debug mode ArrayRangeException is thrown, and unspecified behaviour in Release mode)
String.sub string (String.length string - n) n OCaml (if n is larger than length of string, raises Invalid_argument)
string.sub(string, -n)
(string):sub(-n)
Lua
string last: n Smalltalk (Squeak, Pharo)
/* Examples in REXX */
right("abcde", 3)              /* returns "cde"      */
right("abcde", 8)              /* returns "   abcde" */
right("abcde", 8, "*")         /* returns "***abcde" */
; Examples in Scheme
(use-modules (srfi srfi-13))
(string-take-right "abcde", 3) ;  returns "cde" 
(string-take-right "abcde", 8) ;  error
' Examples in Visual Basic
Right("sandroguidi", 3)        '  returns "idi" 
Right("sandroguidi", 100)      '  returns "sandroguidi"
// Examples in Java; extract rightmost 4 characters
String str = "CarDoor";
str.substring(str.length()-4); // returns 'Door'


rpartition

Definition <string>.rpartition(separator) Searches for the separator from right-to-left within the string then returns the sub-string before the separator; the separator; then the sub-string after the separator.
Description Splits the given string by the right-most separator and returns the three substrings that together make the original.
Format Languages
string.rpartition(separator) Python, Ruby
# Examples in Python
"Spam eggs spam spam and ham".rpartition('spam')  ### ('Spam eggs spam ', 'spam', ' and ham')
"Spam eggs spam spam and ham".rpartition('X')     ### ("", "", 'Spam eggs spam spam and ham')

slice

see #substring


split

Definition <string>.split(separator[, limit]) splits a string on separator, optionally only up to a limited number of substrings
Description Splits the given string by occurrences of the separator (itself a string) and returns a list (or array) of the substrings. If limit is given, after limit - 1 separators have been read, the rest of the string is made into the last substring, regardless of whether it has any separators in it. The Scheme and Erlang implementations are similar but differ in several ways. JavaScript differs also in that it cuts, it does not put the rest of the string into the last element. See the example here. Opposite of join.
Format Languages
split(/separator/, string«, limit») Perl
explode(separator, string«, limit») PHP
string.split(separator«, limit-1») Python
string.split(separator«, limit») Javascript, Java, Ruby
string:tokens(string, sepchars) Erlang
strings.Split(string, separator)
strings.SplitN(string, separator, limit)
Go
(string-tokenize string« charset« start« end»»») Scheme (SRFI 13)
Split(string, sepchars«, limit») VB
string.Split(sepchars«, limit«, options»») VB .NET, C#, F#
string -split separator«, limit«, options»» Windows PowerShell
Str.split (Str.regexp_string separator) string OCaml
std.string.split(string, separator) D
[string componentsSeparatedByString:separator] Objective-C (NSString * only)
TStringList.Delimiter, TStringList.DelimitedText Object Pascal
// Example in C#
"abc,defgh,ijk".Split(',');                 // {"abc", "defgh", "ijk"}
"abc,defgh;ijk".Split(',', ';');            // {"abc", "defgh", "ijk"}
% Example in Erlang
string:tokens("abc;defgh;ijk", ";").        %  ["abc", "defgh", "ijk"]
// Examples in Java
"abc,defgh,ijk".split(",");                 // {"abc", "defgh", "ijk"}
"abc,defgh;ijk".split(",|;");               // {"abc", "defgh", "ijk"}
# Example in Pascal
var
  lStrings: TStringList;
  lStr: string;
begin
  lStrings := TStringList.Create;
  lStrings.Delimiter := ',';
  lStrings.DelimitedText := 'abc,defgh,ijk';
  lStr := lStrings.Strings[0]; // 'abc'
  lStr := lStrings.Strings[1]; // 'defgh'
  lStr := lStrings.Strings[2]; // 'ijk'
end;
# Examples in Perl
split(/spam/, 'Spam eggs spam spam and ham'); # ('Spam eggs ', ' ', ' and ham')
split(/X/, 'Spam eggs spam spam and ham');    #  ('Spam eggs spam spam and ham')

sprintf

see #Format

strip

see #trim


strcmp

see #Compare (integer result)


substring1

Definition substring(string, startpos, endpos) returns string
substr(string, startpos, numChars) returns string
Description Returns a substring of string between starting at startpos and endpos, or starting at startpos of length numChars. The resulting string is truncated if there are fewer than numChars characters beyond the starting point. endpos represents the index after the last character in the substring.
Format Languages
string[startpos:endpos] ALGOL 68 (changes base index)
string (startpos .. endpos) Ada (changes base index)
Mid(string, startpos, numChars) VB
mid(string, startpos, numChars) FreeBASIC
substr(string, startpos, numChars) AWK (changes string), Perl2,4, PHP2,4
substr(string, startpos «,numChars, padChar») REXX
string[startpos:endpos] Python2,3, Go
string[startpos, numChars]
string[startpos .. endpos-1]
string[startpos ... endpos]
Ruby2,3
string.slice(startpos«, endpos») JavaScript2,3
string.substr(startpos«, numChars») C++ (std::string only), JavaScript
string.Substring(startpos, numChars) VB .NET, C#, Windows PowerShell, F#
string.substring(startpos«, endpos») Java, JavaScript
copy(string, startpos, numChars) Object Pascal (Delphi)
(substring string startpos endpos) Scheme
(subseq string startpos endpos) Common Lisp
String.sub string startpos numChars Ocaml
substring (string, startpos, numChars) Standard ML
string:sub_string(string, startpos, endpos)
string:substr(string, startpos, numChars)
Erlang
char result[numChars+1] = "";
strncat(result, string + startpos, numChars);
C
string[startpos .. endpos+1) D
take numChars $ drop startpos string Haskell
[string substringWithRange:NSMakeRange(startpos, numChars)] Objective-C (NSString * only)
string.[startpos..endpos] F#
string.sub(string, startpos, endpos)
(string):sub(startpos, endpos)
Lua2,3
string copyFrom: startpos to: endpos Smalltalk
string(startpos:endpos) Fortran
SUBSTRING(string FROM startpos «FOR numChars») SQL
  1. See CharAt for base of startpos/endpos.
  2. In this language, startpos can be negative, which indicates to start that number of places before the end of the string.
  3. In this language, endpos can be negative, which indicates to end that number of places before the end of the string.
  4. In this language, numChars can be negative, which indicates to end that number of places before the end of the string.
// Examples in C#
"abc".Substring(1, 1):      // returns "b"
"abc".Substring(1, 2);      // returns "bc"
"abc".Substring(1, 6);      // error
;; Examples in Common Lisp
(subseq "abc" 1 2)          ; returns "b"
(subseq "abc" 2)            ; returns "bc"
 
<source lang="text">
% Examples in Erlang
string:substr("abc", 2, 1). %  returns "b"
string:substr("abc", 2).    %  returns "bc"
# Examples in Python
"abc"[1:2]                 #  returns "b"
"abc"[1:3]                 #  returns "bc"
/* Examples in REXX */
substr("abc", 2, 1)         /* returns "b"      */
substr("abc", 2)            /* returns "bc"     */
substr("abc", 2, 6)         /* returns "bc    " */
substr("abc", 2, 6, "*")    /* returns "bc****" */


Uppercase

Definition uppercase(string) returns string
Description Returns the string in upper case.
Format Languages
UCase(string) VB
ucase(string) FreeBASIC
toupper(string) AWK (changes string)
uc(string) Perl
toupper(char) C (operates on one character)
std.string.toupper(string) D
transform(string.begin(), string.end(), result.begin(), toupper)[3] C++ (std::string only, result is stored in string result which is at least as long as string, and may or may not be string itself)
uppercase(string) Object Pascal (Delphi)
upcase(char) Object Pascal (Delphi) (operates on one character)
strtoupper(string) PHP
echo "string" | tr 'a-z' 'A-Z' Unix
translate(string) , or

UPPER variables , or
PARSE UPPER VAR SrcVar DstVar

REXX
string.upper() Python
string.upcase Ruby (only ASCII characters as Ruby lacks Unicode support)
strings.ToUpper(string) Go
(string-upcase string) Scheme, Common Lisp
String.uppercase string OCaml
String.map Char.toUpper string Standard ML
map Char.toUpper string Haskell
string.toUpperCase() Java, JavaScript
to_upper(string) Erlang
string.ToUpper() VB .NET, C#, Windows PowerShell, F#
[string uppercaseString] Objective-C (NSString * only)
string.upper(string)
(string):upper()
Lua
string asUppercase Smalltalk
UPPER(string) SQL
// Example in C#
"Wiki means fast?".ToUpper();      // "WIKI MEANS FAST?"
/* Example in REXX */
translate("Wiki means fast?")      /* "WIKI MEANS FAST?" */
 
/* Example #2 */
A='This is an example.'
UPPER A                            /* "THIS IS AN EXAMPLE." */
 
/* Example #3 */
A='upper using Translate Function.'
Translate UPPER VAR A Z            /* Z="UPPER USING TRANSLATE FUNCTION." */
; Example in Scheme
(use-modules (srfi srfi-13))
(string-upcase "Wiki means fast?") ;  "WIKI MEANS FAST?"
' Example in Visual Basic
UCase("Wiki means fast?")          '  "WIKI MEANS FAST?"

trim

trim or strip is used to remove whitespace from the beginning, end, or both beginning and end, of a string.

Notes

  1. ^ http://fortranwiki.org/fortran/show/scan
  2. ^ http://fortranwiki.org/fortran/show/verify
  3. ^ a b The transform, tolower, and toupper functions exist in the std:: namespace. You must include the <algorithm> header file for the transform function, and include the <cctype> header file for the tolower and toupper functions. In some compilers, a cast must be made to the tolower or toupper function in order to resolve a function overloading ambiguity; e.g. std::transform(string.begin(), string.end(), result.begin(), (int (*)(int))std::tolower);
  4. ^ a b c d e The "find" string in this construct is interpreted as a regular expression. Certain characters have special meaning in regular expressions. If you want to find a string literally, you need to quote the special characters.

External links


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