String length
Find the character and byte length of a string.
You are encouraged to solve this task according to the task description, using any language you may know.
- Task
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
For example, the character length of "møøse" is 5 but the byte length is 7 in UTF-8 and 10 in UTF-16.
Non-BMP code points (those between 0x10000 and 0x10FFFF) must also be handled correctly: answers should produce actual character counts in code points, not in code unit counts.
Therefore a string like "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" (consisting of the 7 Unicode characters U+1D518 U+1D52B U+1D526 U+1D520 U+1D52C U+1D521 U+1D522) is 7 characters long, not 14 UTF-16 code units; and it is 28 bytes long whether encoded in UTF-8 or in UTF-16.
Please mark your examples with ===Character Length=== or ===Byte Length===.
If your language is capable of providing the string length in graphemes, mark those examples with ===Grapheme Length===.
For example, the string "J̲o̲s̲é̲" ("J\x{332}o\x{332}s\x{332}e\x{301}\x{332}") has 4 user-visible graphemes, 9 characters (code points), and 14 bytes when encoded in UTF-8.
- Metrics
- Counting
- Word frequency
- Letter frequency
- Jewels and stones
- I before E except after C
- Bioinformatics/base count
- Count occurrences of a substring
- Count how many vowels and consonants occur in a string
- Remove/replace
- XXXX redacted
- Conjugate a Latin verb
- Remove vowels from a string
- String interpolation (included)
- Strip block comments
- Strip comments from a string
- Strip a set of characters from a string
- Strip whitespace from a string -- top and tail
- Strip control codes and extended characters from a string
- Anagrams/Derangements/shuffling
- Word wheel
- ABC problem
- Sattolo cycle
- Knuth shuffle
- Ordered words
- Superpermutation minimisation
- Textonyms (using a phone text pad)
- Anagrams
- Anagrams/Deranged anagrams
- Permutations/Derangements
- Find/Search/Determine
- ABC words
- Odd words
- Word ladder
- Semordnilap
- Word search
- Wordiff (game)
- String matching
- Tea cup rim text
- Alternade words
- Changeable words
- State name puzzle
- String comparison
- Unique characters
- Unique characters in each string
- Extract file extension
- Levenshtein distance
- Palindrome detection
- Common list elements
- Longest common suffix
- Longest common prefix
- Compare a list of strings
- Longest common substring
- Find common directory path
- Words from neighbour ones
- Change e letters to i in words
- Non-continuous subsequences
- Longest common subsequence
- Longest palindromic substrings
- Longest increasing subsequence
- Words containing "the" substring
- Sum of the digits of n is substring of n
- Determine if a string is numeric
- Determine if a string is collapsible
- Determine if a string is squeezable
- Determine if a string has all unique characters
- Determine if a string has all the same characters
- Longest substrings without repeating characters
- Find words which contains all the vowels
- Find words which contain the most consonants
- Find words which contains more than 3 vowels
- Find words whose first and last three letters are equal
- Find words with alternating vowels and consonants
- Formatting
- Substring
- Rep-string
- Word wrap
- String case
- Align columns
- Literals/String
- Repeat a string
- Brace expansion
- Brace expansion using ranges
- Reverse a string
- Phrase reversals
- Comma quibbling
- Special characters
- String concatenation
- Substring/Top and tail
- Commatizing numbers
- Reverse words in a string
- Suffixation of decimal numbers
- Long literals, with continuations
- Numerical and alphabetical suffixes
- Abbreviations, easy
- Abbreviations, simple
- Abbreviations, automatic
- Song lyrics/poems/Mad Libs/phrases
- Mad Libs
- Magic 8-ball
- 99 bottles of beer
- The Name Game (a song)
- The Old lady swallowed a fly
- The Twelve Days of Christmas
- Tokenize
- Text between
- Tokenize a string
- Word break problem
- Tokenize a string with escaping
- Split a character string based on change of character
- Sequences
360 Assembly
Assembler 360 use EBCDIC coding, so one character is one byte. The L' atrribute can be seen as the length function for assembler 360.
* String length 06/07/2016
LEN CSECT
USING LEN,15 base register
LA 1,L'C length of C
XDECO 1,PG
XPRNT PG,12
LA 1,L'H length of H
XDECO 1,PG
XPRNT PG,12
LA 1,L'F length of F
XDECO 1,PG
XPRNT PG,12
LA 1,L'D length of D
XDECO 1,PG
XPRNT PG,12
LA 1,L'PG length of PG
XDECO 1,PG
XPRNT PG,12
BR 14 exit length
C DS C character 1
H DS H half word 2
F DS F full word 4
D DS D double word 8
PG DS CL12 string 12
END LEN
- Output:
1 2 4 8 12
6502 Assembly
Most 6502-based computers predate Unicode, so only byte length will be demonstrated for now.
GetStringLength: ;$00 and $01 make up the pointer to the string's base address.
;(Of course, any two consecutive zero-page memory locations can fulfill this role.)
LDY #0 ;Y is both the index into the string and the length counter.
loop_getStringLength:
LDA ($00),y
BEQ exit
INY
JMP loop_getStringLength
exit:
RTS ;string length is now loaded into Y.
68000 Assembly
Byte Length (ASCII)
GetStringLength:
; INPUT: A3 = BASE ADDRESS OF STRING
; RETURNS LENGTH IN D1 (MEASURED IN BYTES)
MOVE.L #0,D1
loop_getStringLength:
MOVE.B (A3)+,D0
CMP #0,D0
BEQ done
ADDQ.L #1,D1
BRA loop_getStringLength
done:
RTS
8086 Assembly
Byte Length
;INPUT: DS:SI = BASE ADDR. OF STRING
;TYPICALLY, MS-DOS USES $ TO TERMINATE STRINGS.
GetStringLength:
xor cx,cx ;this takes fewer bytes to encode than "mov cx,0"
cld ;makes string functions post-inc rather than post-dec.
loop_GetStringLength:
lodsb ;equivalent of "mov al,[ds:si],inc si" except this doesn't alter the flags.
cmp '$'
je done ;if equal, we're finished.
inc cx ;add 1 to length counter. A null string will have a length of zero.
jmp loop_GetStringLength
done:
ret
4D
Byte Length
$length:=Length("Hello, world!")
AArch64 Assembly
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program stringLength64.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM64.inc"
/*********************************/
/* Initialized data */
/*********************************/
.data
sMessResultByte: .asciz "===Byte Length=== : @ \n"
sMessResultChar: .asciz "===Character Length=== : @ \n"
szString1: .asciz "møøse€"
szCarriageReturn: .asciz "\n"
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
sZoneConv: .skip 24
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: // entry of program
ldr x0,qAdrszString1
bl affichageMess // display string
ldr x0,qAdrszCarriageReturn
bl affichageMess
ldr x0,qAdrszString1
mov x1,#0
1: // loop compute length bytes
ldrb w2,[x0,x1]
cmp w2,#0
cinc x1,x1,ne
bne 1b
mov x0,x1 // result display
ldr x1,qAdrsZoneConv
bl conversion10 // call decimal conversion
ldr x0,qAdrsMessResultByte
ldr x1,qAdrsZoneConv // insert conversion in message
bl strInsertAtCharInc
bl affichageMess
ldr x0,qAdrszString1
mov x1,#0
mov x3,#0
2: // loop compute length characters
ldrb w2,[x0,x1]
cmp w2,#0
beq 6f
and x2,x2,#0b11100000 // 3 bytes ?
cmp x2,#0b11100000
bne 3f
add x3,x3,#1
add x1,x1,#3
b 2b
3:
and x2,x2,#0b11000000 // 2 bytes ?
cmp x2,#0b11000000
bne 4f
add x3,x3,#1
add x1,x1,#2
b 2b
4: // else 1 byte
add x3,x3,#1
add x1,x1,#1
b 2b
6:
mov x0,x3
ldr x1,qAdrsZoneConv
bl conversion10 // call decimal conversion
ldr x0,qAdrsMessResultChar
ldr x1,qAdrsZoneConv // insert conversion in message
bl strInsertAtCharInc
bl affichageMess
100: // standard end of the program
mov x0,0 // return code
mov x8,EXIT // request to exit program
svc 0 // perform the system call
qAdrszCarriageReturn: .quad szCarriageReturn
qAdrsMessResultByte: .quad sMessResultByte
qAdrsMessResultChar: .quad sMessResultChar
qAdrszString1: .quad szString1
qAdrsZoneConv: .quad sZoneConv
/********************************************************/
/* File Include fonctions */
/********************************************************/
/* for this file see task include a file in language AArch64 assembly */
.include "../includeARM64.inc"
Action!
PROC Test(CHAR ARRAY s)
PrintF("Length of ""%S"" is %B%E",s,s(0))
RETURN
PROC Main()
Test("Hello world!")
Test("")
RETURN
- Output:
Screenshot from Atari 8-bit computer
Length of "Hello world!" is 12 Length of "" is 0
ActionScript
Byte length
This uses UTF-8 encoding. For other encodings, the ByteArray's writeMultiByte()
method can be used.
package {
import flash.display.Sprite;
import flash.events.Event;
import flash.utils.ByteArray;
public class StringByteLength extends Sprite {
public function StringByteLength() {
if ( stage ) _init();
else addEventListener(Event.ADDED_TO_STAGE, _init);
}
private function _init(e:Event = null):void {
var s1:String = "The quick brown fox jumps over the lazy dog";
var s2:String = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
var s3:String = "José";
var b:ByteArray = new ByteArray();
b.writeUTFBytes(s1);
trace(b.length); // 43
b.clear();
b.writeUTFBytes(s2);
trace(b.length); // 28
b.clear();
b.writeUTFBytes(s3);
trace(b.length); // 5
}
}
}
Character Length
var s1:String = "The quick brown fox jumps over the lazy dog";
var s2:String = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
var s3:String = "José";
trace(s1.length, s2.length, s3.length); // 43, 14, 4
Ada
Byte Length
Str : String := "Hello World";
Length : constant Natural := Str'Size / 8;
The 'Size attribute returns the size of an object in bits. Provided that under "byte" one understands an octet of bits, the length in "bytes" will be 'Size divided to 8. Note that this is not necessarily the machine storage unit. In order to make the program portable, System.Storage_Unit should be used instead of "magic number" 8. System.Storage_Unit yields the number of bits in a storage unit on the current machine. Further, the length of a string object is not the length of what the string contains in whatever measurement units. String as an object may have a "dope" to keep the array bounds. In fact the object length can even be 0, if the compiler optimized the object away. So in most cases "byte length" makes no sense in Ada.
Character Length
Latin_1_Str : String := "Hello World";
UCS_16_Str : Wide_String := "Hello World";
Unicode_Str : Wide_Wide_String := "Hello World";
Latin_1_Length : constant Natural := Latin_1_Str'Length;
UCS_16_Length : constant Natural := UCS_16_Str'Length;
Unicode_Length : constant Natural := Unicode_Str'Length;
The attribute 'Length yields the number of elements of an array. Since strings in Ada are arrays of characters, 'Length is the string length. Ada supports strings of Latin-1, UCS-16 and full Unicode characters. In the example above character length of all three strings is 11. The length of the objects in bits will differ.
Aime
Byte Length
length("Hello, World!")
or
~"Hello, World!"
ALGOL 68
Bits and Bytes Length
BITS bits := bits pack((TRUE, TRUE, FALSE, FALSE)); # packed array of BOOL #
BYTES bytes := bytes pack("Hello, world"); # packed array of CHAR #
print((
"BITS and BYTES are fixed width:", new line,
"bits width:", bits width, ", max bits: ", max bits, ", bits:", bits, new line,
"bytes width: ",bytes width, ", UPB:",UPB STRING(bytes), ", string:", STRING(bytes),"!", new line
))
Output:
BITS and BYTES are fixed width: bits width: +32, max bits: TTTTTTTTTTTTTTTTTTTTTTTTTTTTTTTT, bits:TTFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF bytes width: +32, UPB: +32, string:Hello, world!
Character Length
STRING str := "hello, world";
INT length := UPB str;
printf(($"Length of """g""" is "g(3)l$,str,length));
printf(($l"STRINGS can start at -1, in which case LWB must be used:"l$));
STRING s := "abcd"[@-1];
print(("s:",s, ", LWB:", LWB s, ", UPB:",UPB s, ", LEN:",UPB s - LWB s + 1))
Output:
Length of "hello, world" is +12 STRINGS can start at -1, in which case LWB must be used: s:abcd, LWB: -1, UPB: +2, LEN: +4
Apex
String myString = 'abcd';
System.debug('Size of String', myString.length());
AppleScript
Byte Length
count of "Hello World"
Mac OS X 10.5 (Leopard) includes AppleScript 2.0 which uses only Unicode (UTF-16) character strings. This example has been tested on OSX 10.8.5. Added a combining char for testing.
set inString to "Hello é̦世界"
set byteCount to 0
repeat with c in inString
set t to id of c
if ((count of t) > 0) then
repeat with i in t
set byteCount to byteCount + doit(i)
end repeat
else
set byteCount to byteCount + doit(t)
end if
end repeat
byteCount
on doit(cid)
set n to (cid as integer)
if n > 67108863 then -- 0x3FFFFFF
return 6
else if n > 2097151 then -- 0x1FFFFF
return 5
else if n > 65535 then -- 0xFFFF
return 4
else if n > 2047 then -- 0x07FF
return 3
else if n > 127 then -- 0x7F
return 2
else
return 1
end if
end doit
Character Length
count of "Hello World"
Or:
count "Hello World"
Applesoft BASIC
? LEN("HELLO, WORLD!")
ARM Assembly
/* ARM assembly Raspberry PI */
/* program stringLength.s */
/* REMARK 1 : this program use routines in a include file
see task Include a file language arm assembly
for the routine affichageMess conversion10
see at end of this program the instruction include */
/* for constantes see task include a file in arm assembly */
/************************************/
/* Constantes */
/************************************/
.include "../constantes.inc"
/*********************************/
/* Initialized data */
/*********************************/
.data
sMessResultByte: .asciz "===Byte Length=== : @ \n"
sMessResultChar: .asciz "===Character Length=== : @ \n"
szString1: .asciz "møøse€"
szCarriageReturn: .asciz "\n"
/*********************************/
/* UnInitialized data */
/*********************************/
.bss
sZoneConv: .skip 24
/*********************************/
/* code section */
/*********************************/
.text
.global main
main: @ entry of program
ldr r0,iAdrszString1
bl affichageMess @ display string
ldr r0,iAdrszCarriageReturn
bl affichageMess
ldr r0,iAdrszString1
mov r1,#0
1: @ loop compute length bytes
ldrb r2,[r0,r1]
cmp r2,#0
addne r1,#1
bne 1b
mov r0,r1 @ result display
ldr r1,iAdrsZoneConv
bl conversion10 @ call decimal conversion
ldr r0,iAdrsMessResultByte
ldr r1,iAdrsZoneConv @ insert conversion in message
bl strInsertAtCharInc
bl affichageMess
ldr r0,iAdrszString1
mov r1,#0
mov r3,#0
2: @ loop compute length characters
ldrb r2,[r0,r1]
cmp r2,#0
beq 6f
and r2,#0b11100000 @ 3 bytes ?
cmp r2,#0b11100000
bne 3f
add r3,#1
add r1,#3
b 2b
3:
and r2,#0b11000000 @ 2 bytes ?
cmp r2,#0b11000000
bne 4f
add r3,#1
add r1,#2
b 2b
4: @ else 1 byte
add r3,#1
add r1,#1
b 2b
6:
mov r0,r3
ldr r1,iAdrsZoneConv
bl conversion10 @ call decimal conversion
ldr r0,iAdrsMessResultChar
ldr r1,iAdrsZoneConv @ insert conversion in message
bl strInsertAtCharInc
bl affichageMess
100: @ standard end of the program
mov r0, #0 @ return code
mov r7, #EXIT @ request to exit program
svc #0 @ perform the system call
iAdrszCarriageReturn: .int szCarriageReturn
iAdrsMessResultByte: .int sMessResultByte
iAdrsMessResultChar: .int sMessResultChar
iAdrszString1: .int szString1
iAdrsZoneConv: .int sZoneConv
/***************************************************/
/* ROUTINES INCLUDE */
/***************************************************/
.include "../affichage.inc"
møøse€ ===Byte Length=== : 10 ===Character Length=== : 6
Arturo
Character Length
str: "Hello World"
print ["length =" size str]
- Output:
length = 11
AutoHotkey
Character Length
Msgbox % StrLen("Hello World")
Or:
String := "Hello World"
StringLen, Length, String
Msgbox % Length
Avail
Character Length
Avail represents strings as a tuple of characters, with each character representing a single code point.
|"møøse"|
Byte Length
A UTF-8 byte length can be acquired with the standard library's UTF-8 encoder.
nonBMPString ::= "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
encoder ::= a UTF8 encoder;
bytes ::= encoder process nonBMPString;
|bytes|
// or, as a one-liner
|a UTF8 encoder process "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"|
AWK
Byte Length
From within any code block:
w=length("Hello, world!") # static string example
x=length("Hello," s " world!") # dynamic string example
y=length($1) # input field example
z=length(s) # variable name example
Ad hoc program from command line:
echo "Hello, wørld!" | awk '{print length($0)}' # 14
From executable script: (prints for every line arriving on stdin)
#!/usr/bin/awk -f
{print"The length of this line is "length($0)}
Axe
Axe supports two string encodings: a rough equivalent to ASCII, and a token-based format. These examples are for ASCII.
Byte Length
"HELLO, WORLD"→Str1
Disp length(Str1)▶Dec,i
BaCon
BaCon has full native support for UTF-8 encoding.
PRINT "Bytelen of 'hello': ", LEN("hello")
PRINT "Charlen of 'hello': ", ULEN("hello")
PRINT "Bytelen of 'møøse': ", LEN("møøse")
PRINT "Charlen of 'møøse': ", ULEN("møøse")
PRINT "Bytelen of '𝔘𝔫𝔦𝔠𝔬𝔡𝔢': ", LEN("𝔘𝔫𝔦𝔠𝔬𝔡𝔢")
PRINT "Charlen of '𝔘𝔫𝔦𝔠𝔬𝔡𝔢': ", ULEN("𝔘𝔫𝔦𝔠𝔬𝔡𝔢")
- Output:
Bytelen of 'hello': 5 Charlen of 'hello': 5 Bytelen of 'møøse': 7 Charlen of 'møøse': 5 Bytelen of '𝔘𝔫𝔦𝔠𝔬𝔡𝔢': 28 Charlen of '𝔘𝔫𝔦𝔠𝔬𝔡𝔢': 7
BASIC
Character Length
BASIC only supports single-byte characters. The character "ø" is converted to "°" for printing to the console and length functions, but will still output to a file as "ø".
INPUT a$
PRINT LEN(a$)
ANSI BASIC
The ANSI BASIC needs line numbers.
10 INPUT A$
20 PRINT LEN(A$)
Applesoft BASIC
The GW-BASIC solution works without any changes.
BASIC256
The GW-BASIC solution works without any changes.
Chipmunk Basic
The GW-BASIC solution works without any changes.
MSX Basic
The GW-BASIC solution works without any changes.>
Quite BASIC
The GW-BASIC solution works without any changes.
True BASIC
The GW-BASIC solution works without any changes.
Yabasic
The GW-BASIC solution works without any changes.
ZX Spectrum Basic
The ZX Spectrum needs line numbers:
10 INPUT a$
20 PRINT LEN a$
However, it's not quite as trivial as this.
Byte length
Strings can contain embedded colour codes; an inline INVERSE (CAPS SHIFT + 4) would be represented as CHR$ 20 + CHR$ 1. The LEN function will account for all these bytes. On the flipside, ZX Spectrum keywords are all tokenised, and there's nothing stopping you using them in a string; " RANDOMIZE ", if the keyword is used, will take a single byte (CHR$ 249) rather than the 11 characters it actually uses. The above version of the code will produce byte length.
Character length
Stripping out all entries in the string with codes in the lower 32 will get rid of colour control codes. The character length of a token is not a simple thing to determine, so this version strips them out too by eliminating anything above CHR$ 164 (the last UDG). A 91-entry DATA list of token lengths might be the next step.
10 INPUT a$
20 LET b$=""
30 FOR x=1 TO LEN a$
40 LET k=CODE a$(x)
50 IF k<32 OR k>164 THEN GOTO 70
60 LET b$=b$+a$(k)
70 NEXT x
80 PRINT LEN b$
Grapheme length
Alternatively, the string might include control codes for backspacing and overwriting;
10 LET a$=CHR$ 111+CHR$ 8+CHR$ 21+CHR$ 1+CHR$ 34
will produce an "o" character overprinted with a quotation mark, resulting in a "passable" impression of an umlaut. The above code will reduce this to two characters when the actual printed length is one (byte length is of course five). The other possible workaround is to print the string and calculate the character length based on the resultant change in screen position. (This will only work for a string with a character length that actually fits on the screen, so below about 670.)
10 INPUT a$
20 CLS
30 PRINT a$;
40 LET x=PEEK 23688: LET y=PEEK 23689
50 PRINT CHR$ 13;33-x+32*(24-y)
Commodore BASIC
Commodore BASIC needs line numbers too, and can't use mixed case. When in mixed case mode, everything must be in lower case letters. However, the default is UPPERCASE + graphic characters; thus everything appears as UPPER case character.
10 INPUT A$
20 PRINT LEN(A$)
IS-BASIC
100 INPUT PROMPT "String: ":TX$
110 PRINT LEN(TX$)
QB64
In QB64 a String variable is assumed to be UTF-8 and thus the byte length is the same as character length. That said there are methods to map UTF-16 and UTF-32 to the CP437 (ASCII) table (see, _MAPUNICODE).
Print Len(s$)
Batch File
Byte Length
@echo off
setlocal enabledelayedexpansion
call :length %1 res
echo length of %1 is %res%
goto :eof
:length
set str=%~1
set cnt=0
:loop
if "%str%" equ "" (
set %2=%cnt%
goto :eof
)
set str=!str:~1!
set /a cnt = cnt + 1
goto loop
BBC BASIC
Character Length
INPUT text$
PRINT LEN(text$)
Byte Length
CP_ACP = 0
CP_UTF8 = &FDE9
textA$ = "møøse"
textW$ = " "
textU$ = " "
SYS "MultiByteToWideChar", CP_ACP, 0, textA$, -1, !^textW$, LEN(textW$)/2 TO nW%
SYS "WideCharToMultiByte", CP_UTF8, 0, textW$, -1, !^textU$, LEN(textU$), 0, 0
PRINT "Length in bytes (ANSI encoding) = " ; LEN(textA$)
PRINT "Length in bytes (UTF-16 encoding) = " ; 2*(nW%-1)
PRINT "Length in bytes (UTF-8 encoding) = " ; LEN($$!^textU$)
Output:
Length in bytes (ANSI encoding) = 5 Length in bytes (UTF-16 encoding) = 10 Length in bytes (UTF-8 encoding) = 7
BQN
Strings are arrays of characters in BQN.
Byte Length
Each character is converted to its codepoint, and compared with the respective UTF boundary.
BLen ← {(≠𝕩)+´⥊𝕩≥⌜@+128‿2048‿65536}
Character Length
Character length is just array length.
Len ← ≠
Output
•Show >(⊢⋈⊸∾Len⋈BLen)¨⟨
"møøse"
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
"J̲o̲s̲é̲"
⟩
┌─
╵ "møøse" 5 7
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢" 7 28
"J̲o̲s̲é̲" 8 13
┘
Bracmat
The solutions work with UTF-8 encoded strings.
Byte Length
(ByteLength=
length
. @(!arg:? [?length)
& !length
);
out$ByteLength$𝔘𝔫𝔦𝔠𝔬𝔡𝔢
Answer:
28
Character Length
(CharacterLength=
length c
. 0:?length
& @( !arg
: ?
( %?c
& utf$!c:?k
& 1+!length:?length
& ~
)
?
)
| !length
);
out$CharacterLength$𝔘𝔫𝔦𝔠𝔬𝔡𝔢
Answer:
7
An improved version scans the input string character wise, not byte wise. Thus many string positions that are deemed not to be possible starting positions of UTF-8 are not even tried. The patterns [!p
and [?p
implement a ratchet mechanism. [!p
indicates the start of a character and [?p
remembers the end of the character, which becomes the start position of the next byte.
(CharacterLength=
length c p
. 0:?length:?p
& @( !arg
: ?
( [!p %?c
& utf$!c:?k
& 1+!length:?length
)
([?p&~)
?
)
| !length
);
Later versions of Bracmat have the built in function vap
that "vaporises" a string into "atoms". If the string is UTF-8 encoded, then each "atom" is one UTF-8 character, so the length of the list of atoms is the character length of the input string. The first argument to the vap
function is a function that will be applied to every UTF-8 encoded character in the input string. The outcomes of these function calls are the elements in the resulting list. In the solution below we choose an anonymous function (=.!arg)
that just returns the characters themselves.
(CharacterLength=
length
. vap$((=.!arg).!arg):? [?length&!length
);
Brainf***
Byte Length
There are several limitations Brainf*** has that influence this solution:
- Brainf*** only supports 8-bit numbers in canonical implementations, so it only supports strings of length below 255.
- The rule of thumb in Brainf*** when reading a string is to always store exactly one byte, no matter how much bytes a character represents. That's why this solution is a strictly ByteLength one.
- No way to pass anything to Brainf*** but giving the arguments as input. That's why this program reads a string and outputs the number of bytes in it.
[dot 2C_100000bit_etc.29] is used to print the number from memory.
,----- ----- [>,----- -----] ; read a text until a newline
<[+++++ +++++<] ; restore the original text
>[[-]<[>+<-]>+>]< ; add one to the accumulator cell for every byte read
;; from esolang dot org
>[-]>[-]+>[-]+< [>[-<-<<[->+>+<<]>[-<+>]>>]++++++++++>[-]+>[-]>[-]> [-]<<<<<[->-[>+>>]>[[-<+>]+>+>>]<<<<<]>>-[-<<+>>]<[-]++++++++ [-<++++++>]>>[-<<+>>]<<] <[.[-]<]
[-]+++++ +++++. ; print newline
C
Byte Length
#include <string.h>
int main(void)
{
const char *string = "Hello, world!";
size_t length = strlen(string);
return 0;
}
or by hand:
int main(void)
{
const char *string = "Hello, world!";
size_t length = 0;
const char *p = string;
while (*p++ != '\0') length++;
return 0;
}
or (for arrays of char only)
#include <stdlib.h>
int main(void)
{
char s[] = "Hello, world!";
size_t length = sizeof s - 1;
return 0;
}
Character Length
For wide character strings (usually Unicode uniform-width encodings such as UCS-2 or UCS-4):
#include <stdio.h>
#include <wchar.h>
int main(void)
{
wchar_t *s = L"\x304A\x306F\x3088\x3046"; /* Japanese hiragana ohayou */
size_t length;
length = wcslen(s);
printf("Length in characters = %d\n", length);
printf("Length in bytes = %d\n", sizeof(s) * sizeof(wchar_t));
return 0;
}
Dealing with raw multibyte string
Following code is written in UTF-8, and environment locale is assumed to be UTF-8 too. Note that "møøse" is here directly written in the source code for clarity, which is not a good idea in general. mbstowcs()
, when passed NULL as the first argument, effectively counts the number of chars in given string under current locale.
#include <stdio.h>
#include <stdlib.h>
#include <locale.h>
int main()
{
setlocale(LC_CTYPE, "");
char moose[] = "møøse";
printf("bytes: %d\n", sizeof(moose) - 1);
printf("chars: %d\n", (int)mbstowcs(0, moose, 0));
return 0;
}
output
bytes: 7 chars: 5
C#
Platform: .NET
Character Length
string s = "Hello, world!";
int characterLength = s.Length;
Byte Length
Strings in .NET are stored in Unicode.
using System.Text;
string s = "Hello, world!";
int byteLength = Encoding.Unicode.GetByteCount(s);
To get the number of bytes that the string would require in a different encoding, e.g., UTF8:
int utf8ByteLength = Encoding.UTF8.GetByteCount(s);
C++
Byte Length
#include <string> // (not <string.h>!)
using std::string;
int main()
{
string s = "Hello, world!";
string::size_type length = s.length(); // option 1: In Characters/Bytes
string::size_type size = s.size(); // option 2: In Characters/Bytes
// In bytes same as above since sizeof(char) == 1
string::size_type bytes = s.length() * sizeof(string::value_type);
}
For wide character strings:
#include <string>
using std::wstring;
int main()
{
wstring s = L"\u304A\u306F\u3088\u3046";
wstring::size_type length = s.length() * sizeof(wstring::value_type); // in bytes
}
Character Length
For wide character strings:
#include <string>
using std::wstring;
int main()
{
wstring s = L"\u304A\u306F\u3088\u3046";
wstring::size_type length = s.length();
}
For narrow character strings:
#include <iostream>
#include <codecvt>
int main()
{
std::string utf8 = "\x7a\xc3\x9f\xe6\xb0\xb4\xf0\x9d\x84\x8b"; // U+007a, U+00df, U+6c34, U+1d10b
std::cout << "Byte length: " << utf8.size() << '\n';
std::wstring_convert<std::codecvt_utf8<char32_t>, char32_t> conv;
std::cout << "Character length: " << conv.from_bytes(utf8).size() << '\n';
}
#include <cwchar> // for mbstate_t
#include <locale>
// give the character length for a given named locale
std::size_t char_length(std::string const& text, char const* locale_name)
{
// locales work on pointers; get length and data from string and
// then don't touch the original string any more, to avoid
// invalidating the data pointer
std::size_t len = text.length();
char const* input = text.data();
// get the named locale
std::locale loc(locale_name);
// get the conversion facet of the locale
typedef std::codecvt<wchar_t, char, std::mbstate_t> cvt_type;
cvt_type const& cvt = std::use_facet<cvt_type>(loc);
// allocate buffer for conversion destination
std::size_t bufsize = cvt.max_length()*len;
wchar_t* destbuf = new wchar_t[bufsize];
wchar_t* dest_end;
// do the conversion
mbstate_t state = mbstate_t();
cvt.in(state, input, input+len, input, destbuf, destbuf+bufsize, dest_end);
// determine the length of the converted sequence
std::size_t length = dest_end - destbuf;
// get rid of the buffer
delete[] destbuf;
// return the result
return length;
}
Example usage (note that the locale names are OS specific):
#include <iostream>
int main()
{
// Tür (German for door) in UTF8
std::cout << char_length("\x54\xc3\xbc\x72", "de_DE.utf8") << "\n"; // outputs 3
// Tür in ISO-8859-1
std::cout << char_length("\x54\xfc\x72", "de_DE") << "\n"; // outputs 3
}
Note that the strings are given as explicit hex sequences, so that the encoding used for the source code won't matter.
Clean
Byte Length
Clean Strings are unboxed arrays of characters. Characters are always a single byte. The function size returns the number of elements in an array.
import StdEnv
strlen :: String -> Int
strlen string = size string
Start = strlen "Hello, world!"
Clojure
Byte Length
(def utf-8-octet-length #(-> % (.getBytes "UTF-8") count))
(map utf-8-octet-length ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (7 28 14)
(def utf-16-octet-length (comp (partial * 2) count))
(map utf-16-octet-length ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (10 28 18)
(def code-unit-length count)
(map code-unit-length ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (5 14 9)
Character length
(def character-length #(.codePointCount % 0 (count %)))
(map character-length ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (5 7 9)
Grapheme Length
(def grapheme-length
#(->> (doto (java.text.BreakIterator/getCharacterInstance)
(.setText %))
(partial (memfn next))
repeatedly
(take-while (partial not= java.text.BreakIterator/DONE))
count))
(map grapheme-length ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (5 7 4)
COBOL
Byte Length
FUNCTION BYTE-LENGTH(str)
Alternative, non-standard extensions:
LENGTH OF str
FUNCTION LENGTH-AN(str)
Character Length
FUNCTION LENGTH(str)
ColdFusion
Byte Length
<cfoutput>
<cfset str = "Hello World">
<cfset j = createObject("java","java.lang.String").init(str)>
<cfset t = j.getBytes()>
<p>#arrayLen(t)#</p>
</cfoutput>
Character Length
#len("Hello World")#
Common Lisp
Byte Length
In Common Lisp, there is no standard way to examine byte representations of characters, except perhaps to write a string to a file, then reopen the file as binary. However, specific implementations will have ways to do so. For example:
(length (sb-ext:string-to-octets "Hello Wørld"))
returns 12.
Character Length
Common Lisp represents strings as sequences of characters, not bytes, so there is no ambiguity about the encoding. The length function always returns the number of characters in a string.
(length "Hello World")
returns 11, and
(length "Hello Wørld")
returns 11 too.
Component Pascal
Component Pascal encodes strings in UTF-16, which represents each character with 16-bit value.
Character Length
MODULE TestLen;
IMPORT Out;
PROCEDURE DoCharLength*;
VAR s: ARRAY 16 OF CHAR; len: INTEGER;
BEGIN
s := "møøse";
len := LEN(s$);
Out.String("s: "); Out.String(s); Out.Ln;
Out.String("Length of characters: "); Out.Int(len, 0); Out.Ln
END DoCharLength;
END TestLen.
A symbol $ in LEN(s$) in Component Pascal allows to copy sequence of characters up to null-terminated character. So, LEN(s$) returns a real length of characters instead of allocated by variable.
Running command TestLen.DoCharLength gives following output:
s: møøse Length of characters: 5
Byte Length
MODULE TestLen;
IMPORT Out;
PROCEDURE DoByteLength*;
VAR s: ARRAY 16 OF CHAR; len, v: INTEGER;
BEGIN
s := "møøse";
len := LEN(s$);
v := SIZE(CHAR) * len;
Out.String("s: "); Out.String(s); Out.Ln;
Out.String("Length of characters in bytes: "); Out.Int(v, 0); Out.Ln
END DoByteLength;
END TestLen.
Running command TestLen.DoByteLength gives following output:
s: møøse Length of characters in bytes: 10
Crystal
UTF8 is the default encoding in Crystal.
Byte Length
"J̲o̲s̲é̲".bytesize
Character Length
"J̲o̲s̲é̲".chars.length
D
Byte Length
import std.stdio;
void showByteLen(T)(T[] str) {
writefln("Byte length: %2d - %(%02x%)",
str.length * T.sizeof, cast(ubyte[])str);
}
void main() {
string s1a = "møøse"; // UTF-8
showByteLen(s1a);
wstring s1b = "møøse"; // UTF-16
showByteLen(s1b);
dstring s1c = "møøse"; // UTF-32
showByteLen(s1c);
writeln();
string s2a = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
showByteLen(s2a);
wstring s2b = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
showByteLen(s2b);
dstring s2c = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
showByteLen(s2c);
writeln();
string s3a = "J̲o̲s̲é̲";
showByteLen(s3a);
wstring s3b = "J̲o̲s̲é̲";
showByteLen(s3b);
dstring s3c = "J̲o̲s̲é̲";
showByteLen(s3c);
}
- Output:
Byte length: 7 - 6dc3b8c3b87365 Byte length: 10 - 6d00f800f80073006500 Byte length: 20 - 6d000000f8000000f80000007300000065000000 Byte length: 28 - f09d9498f09d94abf09d94a6f09d94a0f09d94acf09d94a1f09d94a2 Byte length: 28 - 35d818dd35d82bdd35d826dd35d820dd35d82cdd35d821dd35d822dd Byte length: 28 - 18d501002bd5010026d5010020d501002cd5010021d5010022d50100 Byte length: 14 - 4accb26fccb273ccb265cc81ccb2 Byte length: 18 - 4a0032036f00320373003203650001033203 Byte length: 36 - 4a000000320300006f000000320300007300000032030000650000000103000032030000
Character Length
import std.stdio, std.range, std.conv;
void showCodePointsLen(T)(T[] str) {
writefln("Character length: %2d - %(%x %)",
str.walkLength(), cast(uint[])to!(dchar[])(str));
}
void main() {
string s1a = "møøse"; // UTF-8
showCodePointsLen(s1a);
wstring s1b = "møøse"; // UTF-16
showCodePointsLen(s1b);
dstring s1c = "møøse"; // UTF-32
showCodePointsLen(s1c);
writeln();
string s2a = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
showCodePointsLen(s2a);
wstring s2b = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
showCodePointsLen(s2b);
dstring s2c = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
showCodePointsLen(s2c);
writeln();
string s3a = "J̲o̲s̲é̲";
showCodePointsLen(s3a);
wstring s3b = "J̲o̲s̲é̲";
showCodePointsLen(s3b);
dstring s3c = "J̲o̲s̲é̲";
showCodePointsLen(s3c);
}
- Output:
Character length: 5 - 6d f8 f8 73 65 Character length: 5 - 6d f8 f8 73 65 Character length: 5 - 6d f8 f8 73 65 Character length: 7 - 1d518 1d52b 1d526 1d520 1d52c 1d521 1d522 Character length: 7 - 1d518 1d52b 1d526 1d520 1d52c 1d521 1d522 Character length: 7 - 1d518 1d52b 1d526 1d520 1d52c 1d521 1d522 Character length: 9 - 4a 332 6f 332 73 332 65 301 332 Character length: 9 - 4a 332 6f 332 73 332 65 301 332 Character length: 9 - 4a 332 6f 332 73 332 65 301 332
DataWeave
Character Length
sizeOf("foo")
- Output:
3
Dc
Byte Length
Dc's "P" command prints numbers as strings. The number 22405534230753963835153736737 (hint: look at it in hex) represents "Hello world!". Counting the byte length of it is counting how often it iteratively can be divided by 256 with non zero result. The snippet defines the macro which calculates the length, prints the string 1st and then its length.
[256 / d 0<L 1 + ] sL
22405534230753963835153736737 d P A P
lL x f
Hello world! 12
Character Length
The following code output 5, which is the length of the string "abcde"
[abcde]Zp
Déjà Vu
Byte Length
Byte length depends on the encoding, which internally is UTF-8, but users of the language can only get at the raw bytes after encoding a string into a blob.
!. len !encode!utf-8 "møøse"
!. len !encode!utf-8 "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
- Output:
7 28
Character Length
!. len "møøse"
!. len "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
- Output:
5 7
Delphi
See Pascal.
DuckDB
select s, length(s), strlen(s) as '# bytes' from
(select unnest(['J̲o̲s̲é̲', '𝔘𝔫𝔦𝔠𝔬𝔡𝔢']) as s);
- Output:
┌─────────┬───────────┬─────────┐ │ s │ length(s) │ # bytes │ │ varchar │ int64 │ int64 │ ├─────────┼───────────┼─────────┤ │ J̲o̲s̲é̲ │ 8 │ 13 │ │ 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 │ 7 │ 28 │ └─────────┴───────────┴─────────┘
Dyalect
"Hello World".Length()
E
Character Length
"Hello World".size()
EasyLang
print len "møøse"
print len "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
print len "J̲o̲s̲é̲"
print len "😀"
- Output:
5 7 8 1
Ecstasy
module StrLen {
@Inject Console console;
void run(String s = "José") {
console.print($|For the string {s.quoted()}:
| Character length: {s.size}
| UTF-8 byte length: {s.calcUtf8Length()}
);
}
}
- Output:
For the string "José": Character length: 4 UTF-8 byte length: 5
Ed
Character Length
Uses unary i-encoded numbers for string length. Predictably over-estimates the length by one character due to newline handling hack.
H
,p
g/./s//i/g
g/^/s//i/
,j
# unary -> decimal (for 0-10000 range)
g/i{9000}(i{0,999})/s//9\1/
g/i{8000}(i{0,999})/s//8\1/
g/i{7000}(i{0,999})/s//7\1/
g/i{6000}(i{0,999})/s//6\1/
g/i{5000}(i{0,999})/s//5\1/
g/i{4000}(i{0,999})/s//4\1/
g/i{3000}(i{0,999})/s//3\1/
g/i{2000}(i{0,999})/s//2\1/
g/i{1000}(i{0,999})/s//1\1/
v/^[0-9]i*$/s/.*/0&/
g/i{900}(i{0,99})/s//9\1/
g/i{800}(i{0,99})/s//8\1/
g/i{700}(i{0,99})/s//7\1/
g/i{600}(i{0,99})/s//6\1/
g/i{500}(i{0,99})/s//5\1/
g/i{400}(i{0,99})/s//4\1/
g/i{300}(i{0,99})/s//3\1/
g/i{200}(i{0,99})/s//2\1/
g/i{100}(i{0,99})/s//1\1/
v/^[0-9]{2}i*$/s/^([0-9])(i*)$/\10\2/
g/i{90}(i{0,9})/s//9\1/
g/i{80}(i{0,9})/s//8\1/
g/i{70}(i{0,9})/s//7\1/
g/i{60}(i{0,9})/s//6\1/
g/i{50}(i{0,9})/s//5\1/
g/i{40}(i{0,9})/s//4\1/
g/i{30}(i{0,9})/s//3\1/
g/i{20}(i{0,9})/s//2\1/
g/i{10}(i{0,9})/s//1\1/
v/^[0-9]{3}i*$/s/^([0-9]{2})(i*)$/\10\2/
g/i{9}/s//9/
g/i{8}/s//8/
g/i{7}/s//7/
g/i{6}/s//6/
g/i{5}/s//5/
g/i{4}/s//4/
g/i{3}/s//3/
g/i{2}/s//2/
g/i{1}/s//1/
v/^[0-9]{4}i*$/s/^([0-9]{3})(i*)$/\10\2/
g/0+([0-9])/s//\1/
,p
Q
Elena
Character Length
ELENA 4.x :
import extensions;
public program()
{
var s := "Hello, world!"; // UTF-8 literal
var ws := "Привет мир!"w; // UTF-16 literal
var s_length := s.Length; // Number of UTF-8 characters
var ws_length := ws.Length; // Number of UTF-16 characters
var u_length := ws.toArray().Length; //Number of UTF-32 characters
}
Byte Length
ELENA 4.x :
import extensions;
public program()
{
var s := "Hello, world!"; // UTF-8 literal
var ws := "Привет мир!"w; // UTF-16 literal
var s_byte_length := s.toByteArray().Length; // Number of bytes
var ws_byte_length := ws.toByteArray().Length; // Number of bytes
}
Elixir
Byte Length
name = "J\x{332}o\x{332}s\x{332}e\x{301}\x{332}"
byte_size(name)
# => 14
Character Length
name = "J\x{332}o\x{332}s\x{332}e\x{301}\x{332}"
Enum.count(String.codepoints(name))
# => 9
Grapheme Length
name = "J\x{332}o\x{332}s\x{332}e\x{301}\x{332}"
String.length(name)
# => 4
Emacs Lisp
Character Length
(length "hello")
;; => 5
Byte Length
(string-bytes "\u1D518\u1D52B\u1D526")
;; => 12
string-bytes
is the length of Emacs' internal representation. In Emacs 23 up this is utf-8. In earlier versions it was "emacs-mule".
Display Length
string-width
is the displayed width of a string in the current frame and window. This is not the same as grapheme length since various Asian characters may display in 2 columns, depending on the type of tty or GUI.
(let ((str (apply 'string
(mapcar (lambda (c) (decode-char 'ucs c))
'(#x1112 #x1161 #x11ab #x1100 #x1173 #x11af)))))
(list (length str)
(string-bytes str)
(string-width str)))
;; => (6 18 4) ;; in emacs 23 up
EMal
text moose = "møøse"
text unicode = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
text jose = "J" + 0U0332 + "o" + 0U0332 + "s" + 0U0332 + "e" + 0U0301 + 0U0332
text emoji = "𠇰😈🎶🔥é-"
Byte Length
writeLine((blob!moose).length)
writeLine((blob!unicode).length)
writeLine((blob!jose).length)
writeLine((blob!emoji).length)
- Output:
7 28 14 19
Character Length
writeLine(moose.codePointsLength)
writeLine(unicode.codePointsLength)
writeLine(jose.codePointsLength)
writeLine(emoji.codePointsLength)
- Output:
5 7 9 6
Grapheme Length
writeLine(moose.graphemesLength)
writeLine(unicode.graphemesLength)
writeLine(jose.graphemesLength)
writeLine(emoji.graphemesLength)
- Output:
5 7 4 6
Erlang
Character Length
Strings are lists of integers in Erlang. So "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" is the list [120088,120107,120102,120096,120108,120097,120098].
9> U = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢". [120088,120107,120102,120096,120108,120097,120098] 10> erlang:length(U). 7
Euphoria
Character Length
print(1,length("Hello World"))
F#
This is delegated to the standard .Net framework string and encoding functions.
Byte Length
open System.Text
let byte_length str = Encoding.UTF8.GetByteCount(str)
Character Length
"Hello, World".Length
Factor
Byte Length
Here are two words to compute the byte length of strings. The first one doesn't allocate new memory, the second one can easily be adapted to measure the byte length of encodings other than UTF8.
: string-byte-length ( string -- n ) [ code-point-length ] map-sum ;
: string-byte-length-2 ( string -- n ) utf8 encode length ;
Character Length
length
works on any sequece, of which strings are one. Strings are UTF8 encoded.
length
Fantom
Byte length
A string can be converted into an instance of Buf
to treat the string as a sequence of bytes according to a given charset: the default is UTF8, but 16-bit representations can also be used.
fansh> c := "møøse"
møøse
fansh> c.toBuf.size // find the byte length of the string in default (UTF8) encoding
7
fansh> c.toBuf.toHex // display UTF8 representation
6dc3b8c3b87365
fansh> c.toBuf(Charset.utf16LE).size // byte length in UTF16 little-endian
10
fansh> c.toBuf(Charset.utf16LE).toHex // display as UTF16 little-endian
6d00f800f80073006500
fansh> c.toBuf(Charset.utf16BE).size // byte length in UTF16 big-endian
10
fansh> c.toBuf(Charset.utf16BE).toHex // display as UTF16 big-endian
006d00f800f800730065
Character length
fansh> c := "møøse"
møøse
fansh> c.size
5
Forth
Byte Length
Strings in Forth come in two forms, neither of which are the null-terminated form commonly used in the C standard library.
Counted string
A counted string is a single pointer to a short string in memory. The string's first byte is the count of the number of characters in the string. This is how symbols are stored in a Forth dictionary.
CREATE s ," Hello world" \ create string "s"
s C@ ( -- length=11 )
s COUNT ( addr len ) \ convert to a stack string, described below
Stack string
A string on the stack is represented by a pair of cells: the address of the string data and the length of the string data (in characters). The word COUNT converts a counted string into a stack string. The STRING utility wordset of ANS Forth works on these addr-len pairs. This representation has the advantages of not requiring null-termination, easy representation of substrings, and not being limited to 255 characters.
S" string" ( addr len)
DUP . \ 6
Character Length
The 1994 ANS standard does not have any notion of a particular character encoding, although it distinguishes between character and machine-word addresses. (There is some ongoing work on standardizing an "XCHAR" wordset for dealing with strings in particular encodings such as UTF-8.)
The following code will count the number of UTF-8 characters in a null-terminated string. It relies on the fact that all bytes of a UTF-8 character except the first have the the binary bit pattern "10xxxxxx".
2 base !
: utf8+ ( str -- str )
begin
char+
dup c@
11000000 and
10000000 <>
until ;
decimal
: count-utf8 ( zstr -- n )
0
begin
swap dup c@
while
utf8+
swap 1+
repeat drop ;
Fortran
Fortran 77 introduced variables of type CHARACTER and associated syntax. These are fixed-size entities, declared at compile time as in CHARACTER*66 TEXT
, however a subroutine (or function) receiving such a variable could declare it as CHARACTER*(*) TEXT
so that any size may be supplied to the routine, and with F90 came the ability within subroutines (or functions) to declare items of a size determined at run time. There is no associated length variable, as with strings that have both a content and a length, nor is there a special character value (such as zero) deemed to mark the end-of-text in such a variable to give string-like facilities. However, with F90 came facilities, standardised in F2003 whereby a CHARACTER variable could be re-allocated exactly the right amount of storage whenever it was assigned to. So, TEXT = "this"
would cause TEXT to become a CHARACTER variable of length four, adjusted so at run time. Again, the length information is not associated with the variable itself, for instance as the content of a character zero prefixing the content to enable strings of a length up to 255. The length information must be stored somewhere...
Previously, character data would be stored in arithmetic variables, using format codes such as A1
to store one character per variable, which might be an integer or a floating-point variable of much larger size. Format A2
would store two such characters, and so on. Code A1 would give ease of manipulation, while A8 (say for a REAL*8 variable) would save space. Numerical values would be strange, and word sizes may not be a multiple of eight bits nor character encodements require eight bits, especially on a decimal computer such as the IBM1620 where storage usage was counted in digits, and a character required two.
An intrinsic function LEN(text) reports the number of characters in the variable (with no consideration of any storage needed anywhere to hold the length), while SIZE(array) reports the number of elements in an array and SIZEOF(x) may be available to report the number of bytes of storage of x. Since these days, everyone uses computers with eight-bit characters and this is deemed universal, the result from LEN will be equivalent to both a byte and a character count.
There is no facility for fancy Unicode schemes, other than by writing suitable routines. In that regard, plotting packages often supply a special function that returns the length of a text string, as it would appear on the plot, in plotting units, especially useful when the plotter's rendition of text employs a proportionally-spaced typeface and interprets superscripts and subscripts and so forth, so that the programmer can prepare code to juggle with the layout, perhaps of mathematical expressions. This is of course not in any standard.
Byte Length
LEN(text)
Character Length
LEN(text)
FreeBASIC
' FB 1.05.0 Win64
Dim s As String = "moose" '' variable length ascii string
Dim f As String * 5 = "moose" '' fixed length ascii string (in practice a zero byte is appended)
Dim z As ZString * 6 = "moose" '' fixed length zero terminated ascii string
Dim w As WString * 6 = "møøse" '' fixed length zero terminated unicode string
' Variable length strings have a descriptor consisting of 3 Integers (12 bytes on 32 bit, 24 bytes on 64 bit systems)
' In order, the descriptor contains the address of the data, the memory currently used and the memory allocated
' In Windows, WString uses UCS-2 encoding (i.e. 2 bytes per character, surrogates are not supported)
' In Linux, WString uses UCS-4 encoding (i.e. 4 bytes per character)
' The Len function always returns the length of the string in characters
' The SizeOf function returns the bytes used (by the descriptor in the case of variable length strings)
Print "s : " ; s, "Character Length : "; Len(s), "Byte Length : "; Len(s); " (data)"
Print "s : " ; s, "Character Length : "; Len(s), "Byte Length : "; SizeOf(s); " (descriptor)"
Print "f : " ; f, "Character Length : "; Len(s), "Byte Length : "; SizeOf(f)
Print "z : " ; z, "Character Length : "; Len(s), "Byte Length : "; SizeOf(z)
Print "w : " ; w, "Character Length : "; Len(s), "Byte Length : "; SizeOf(w)
Print
Sleep
- Output:
s : moose Character Length : 5 Byte Length : 5 (data) s : moose Character Length : 5 Byte Length : 24 (descriptor) f : moose Character Length : 5 Byte Length : 6 z : moose Character Length : 5 Byte Length : 6 w : møøse Character Length : 5 Byte Length : 12
Frink
Byte Length
A string can be converted to an array of bytes in any supported encoding.
b = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
length[stringToBytes[b, "UTF-8"]]
Character Length
Frink's string operations correctly handle upper-plane Unicode characters as a single codepoint.
b = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
length[b]
Grapheme Length
b = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
graphemeLength[b]
GAP
Length("abc");
# or same result with
Size("abc");
Gnuplot
Byte Length
print strlen("hello")
=> 5
Go
Byte Length
package main
import "fmt"
func main() {
m := "møøse"
u := "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
j := "J̲o̲s̲é̲"
fmt.Printf("%d %s % x\n", len(m), m, m)
fmt.Printf("%d %s % x\n", len(u), u, u)
fmt.Printf("%d %s % x\n", len(j), j, j)
}
Output:
7 møøse 6d c3 b8 c3 b8 73 65 28 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 f0 9d 94 98 f0 9d 94 ab f0 9d 94 a6 f0 9d 94 a0 f0 9d 94 ac f0 9d 94 a1 f0 9d 94 a2 13 J̲o̲s̲é̲ 4a cc b2 6f cc b2 73 cc b2 c3 a9 cc b2
Character Length
package main
import (
"fmt"
"unicode/utf8"
)
func main() {
m := "møøse"
u := "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
j := "J̲o̲s̲é̲"
fmt.Printf("%d %s %x\n", utf8.RuneCountInString(m), m, []rune(m))
fmt.Printf("%d %s %x\n", utf8.RuneCountInString(u), u, []rune(u))
fmt.Printf("%d %s %x\n", utf8.RuneCountInString(j), j, []rune(j))
}
Output:
5 møøse [6d f8 f8 73 65] 7 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 [1d518 1d52b 1d526 1d520 1d52c 1d521 1d522] 9 J̲o̲s̲é̲ [4a 332 6f 332 73 332 65 301 332]
Grapheme Length
Go does not have language or library features to recognize graphemes directly. For example, it does not provide functions implementing Unicode Standard Annex #29, Unicode Text Segmentation. It does however have convenient functions for recognizing Unicode character categories, and so an expected subset of grapheme possibilites is easy to recognize. Here is a solution recognizing the category "Mn", which includes the combining characters used in the task example.
package main
import (
"fmt"
"unicode"
"unicode/utf8"
)
func main() {
m := "møøse"
u := "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
j := "J̲o̲s̲é̲"
fmt.Printf("%d %s %x\n", grLen(m), m, []rune(m))
fmt.Printf("%d %s %x\n", grLen(u), u, []rune(u))
fmt.Printf("%d %s %x\n", grLen(j), j, []rune(j))
}
func grLen(s string) int {
if len(s) == 0 {
return 0
}
gr := 1
_, s1 := utf8.DecodeRuneInString(s)
for _, r := range s[s1:] {
if !unicode.Is(unicode.Mn, r) {
gr++
}
}
return gr
}
Output:
5 møøse [6d f8 f8 73 65] 7 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 [1d518 1d52b 1d526 1d520 1d52c 1d521 1d522] 4 J̲o̲s̲é̲ [4a 332 6f 332 73 332 65 301 332]
Groovy
Calculating "Byte-length" (by which one typically means "in-memory storage size in bytes") is not possible through the facilities of the Groovy language alone. Calculating "Character length" is built into the Groovy extensions to java.lang.String.
Character Length
println "Hello World!".size()
println "møøse".size()
println "𝔘𝔫𝔦𝔠𝔬𝔡𝔢".size()
println "J̲o̲s̲é̲".size()
Output:
12 5 14 8
Note: The Java "String.length()" method also works in Groovy, but "size()" is consistent with usage in other sequential or composite types.
GW-BASIC
GW-BASIC only supports single-byte characters.
10 INPUT A$
20 PRINT LEN(A$)
Haskell
Byte Length
It is not possible to determine the "byte length" of an ordinary string, because in Haskell, a string is a boxed list of unicode characters. So each character in a string is represented as whatever the compiler considers as the most efficient representation of a cons-cell and a unicode character, and not as a byte.
For efficient storage of sequences of bytes, there's Data.ByteString, which uses Word8 as a base type. Byte strings have an additional Data.ByteString.Char8 interface, which will truncate each Unicode Char to 8 bits as soon as it is converted to a byte string. However, this is not adequate for the task, because truncation simple will garble characters other than Latin-1, instead of encoding them into UTF-8, say.
There are several (non-standard, so far) Unicode encoding libraries available on Hackage. As an example, we'll use encoding-0.2, as Data.Encoding:
import Data.Encoding
import Data.ByteString as B
strUTF8 :: ByteString
strUTF8 = encode UTF8 "Hello World!"
strUTF32 :: ByteString
strUTF32 = encode UTF32 "Hello World!"
strlenUTF8 = B.length strUTF8
strlenUTF32 = B.length strUTF32
Character Length
The base type Char defined by the standard is already intended for (plain) Unicode characters.
strlen = length "Hello, world!"
HicEst
LEN("1 character == 1 byte") ! 21
HolyC
Byte Length
U8 *string = "Hello, world!";
Print("%d\n", StrLen(string));
Icon and Unicon
Character Length
Note: Neither Icon nor Unicon currently supports double-byte character sets.
IDL
Byte Length
Compiler: any IDL compiler should do
length = strlen("Hello, world!")
Character Length
length = strlen("Hello, world!")
Io
Byte Length
"møøse" sizeInBytes
Character Length
"møøse" size
J
Byte Length
# 'møøse'
7
Here we use the default encoding for character literals (8 bit wide literals).
Character Length
#7 u: 'møøse'
5
Here we have used 16 bit wide character literals. See also the dictionary page for u:.
Jakt
Character Length
fn character_length(string: String) -> i64 {
mut length = 0
for _ in string.code_points() {
length++
}
return length
}
fn main() {
for string in [
"Hello world!"
"møøse"
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
"J̲o̲s̲é̲"
] {
println("\"{}\" {}", string, character_length(string))
}
}
- Output:
"Hello world!" 12 "møøse" 5 "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" 7 "J̲o̲s̲é̲" 8
Byte Length
fn main() {
for string in [
"Hello world!"
"møøse"
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
"J̲o̲s̲é̲"
] {
println("\"{}\" {}", string, string.length())
}
}
- Output:
"Hello world!" 12 "møøse" 7 "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" 28 "J̲o̲s̲é̲" 13
Java
Byte Length
Java encodes strings in UTF-16, which represents each character with one or two 16-bit values.
Another way to know the byte length of a string -who cares- is to explicitly specify the charset we desire.
String s = "Hello, world!";
int byteCountUTF16 = s.getBytes("UTF-16").length; // Incorrect: it yields 28 (that is with the BOM)
int byteCountUTF16LE = s.getBytes("UTF-16LE").length; // Correct: it yields 26
int byteCountUTF8 = s.getBytes("UTF-8").length; // yields 13
Character Length
Java encodes strings in UTF-16, which represents each character (code point) with one or two 16-bit code units. This is a variable-length encoding scheme. The most commonly used characters are represented by one 16-bit code unit, while rarer ones like some mathematical symbols are represented by two.
The length method of String objects is not the length of that String in characters. Instead, it only gives the number of 16-bit code units used to encode a string. This is not (always) the number of Unicode characters (code points) in the string.
String s = "Hello, world!";
int not_really_the_length = s.length(); // XXX: does not (always) count Unicode characters (code points)!
Since Java 1.5, the actual number of characters (code points) can be determined by calling the codePointCount method.
String str = "\uD834\uDD2A"; //U+1D12A
int not_really__the_length = str.length(); // value is 2, which is not the length in characters
int actual_length = str.codePointCount(0, str.length()); // value is 1, which is the length in characters
Grapheme Length
Since JDK 20[1].
import java.text.BreakIterator;
public class Grapheme {
public static void main(String[] args) {
printLength("møøse");
printLength("𝔘𝔫𝔦𝔠𝔬𝔡𝔢");
printLength("J̲o̲s̲é̲");
}
public static void printLength(String s) {
BreakIterator it = BreakIterator.getCharacterInstance();
it.setText(s);
int count = 0;
while (it.next() != BreakIterator.DONE) {
count++;
}
System.out.println("Grapheme length: " + count+ " " + s);
}
}
Output:
Grapheme length: 5 møøse Grapheme length: 7 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 Grapheme length: 4 J̲o̲s̲é̲
JavaScript
Byte length
JavaScript encodes strings in UTF-16, which represents each character with one or two 16-bit values. The length property of string objects gives the number of 16-bit values used to encode a string, so the number of bytes can be determined by doubling that number.
var s = "Hello, world!";
var byteCount = s.length * 2; // 26
It's easier to use Buffer.byteLength (Node.JS specific, not ECMAScript).
a = '👩❤️👩'
Buffer.byteLength(a, 'utf16le'); // 16
Buffer.byteLength(a, 'utf8'); // 20
Buffer.byteLength(s, 'utf16le'); // 26
Buffer.byteLength(s, 'utf8'); // 13
In pure ECMAScript, TextEncoder() can be used to return the UTF-8 byte size:
(new TextEncoder().encode(a)).length; // 20
(new TextEncoder().encode(s)).length; // 13
Unicode codepoint length
JavaScript encodes strings in UTF-16, which represents each character with one or two 16-bit values. The most commonly used characters are represented by one 16-bit value, while rarer ones like some mathematical symbols are represented by two.
If the string only contains commonly used characters, the number of characters will be equal to the number of 16-bit values used to represent the characters.
var str1 = "Hello, world!";
var len1 = str1.length; // 13
var str2 = "\uD834\uDD2A"; // U+1D12A represented by a UTF-16 surrogate pair
var len2 = str2.length; // 2
More generally, the expansion operator in an array can be used to enumerate Unicode code points:
[...str2].length // 1
Unicode grapheme length
Counting Unicode codepoints when using combining characters such as joining sequences or diacritics will return the wrong size, so we must count graphemes instead. Intl.Segmenter() default granularity is grapheme.
[...new Intl.Segmenter().segment(a)].length; // 1
ES6 destructuring/iterators
ES6 provides several ways to get a string split into an array of code points instead of UTF-16 code units:
let
str='AöЖ€𝄞'
,countofcodeunits=str.length // 6
,cparr=[...str],
,countofcodepoints=cparr.length; // 5
{ let
count=0
for(let codepoint of str)
count++
countofcodepoints=count // 5
}
{ let
count=0,
it=str[Symbol.iterator]()
while(!it.next().done)
count++
countofcodepoints=count // 5
}
{ cparr=Array.from(str)
countofcodepoints=cparr.length // 5
}
Joy
- Byte length
"Café" size.
- Output:
5
jq
jq strings are JSON strings and are therefore encoded as UTF-8. When given a JSON string, the length filter emits the number of Unicode codepoints that it contains, and the utf8bytelength filter emits the number of bytes.
$ cat String_length.jq
def describe:
"\(.) has \(length) codepoints and \(utf8bytelength) bytes";
("J̲o̲s̲é̲", "𝔘𝔫𝔦𝔠𝔬𝔡𝔢") | describe
$ jq -nr -f String_length.jq
J̲o̲s̲é̲ has 8 codepoints and 13 bytes
𝔘𝔫𝔦𝔠𝔬𝔡𝔢 has 7 codepoints and 28 bytes
JudoScript
Byte Length
//Store length of hello world in length and print it
. length = "Hello World".length();
Character Length
//Store length of hello world in length and print it
. length = "Hello World".length()
Julia
Julia encodes strings as UTF-8, so the byte length (via sizeof
) will be different from the string length (via length
) only if the string contains non-ASCII characters.
Byte Length
sizeof("møøse") # 7
sizeof("𝔘𝔫𝔦𝔠𝔬𝔡𝔢") # 28
sizeof("J̲o̲s̲é̲") # 13
Character Length
length("møøse") # 5
length("𝔘𝔫𝔦𝔠𝔬𝔡𝔢") # 7
length("J̲o̲s̲é̲") # 8
Grapheme Length
import Unicode
length(Unicode.graphemes("møøse")) # 5
length(Unicode.graphemes("𝔘𝔫𝔦𝔠𝔬𝔡𝔢")) # 7
length(Unicode.graphemes("J̲o̲s̲é̲")) # 4
K
Character Length
#"Hello, world!"
13
#"Hëllo, world!"
13
Kotlin
As in Java, a string in Kotlin is essentially a sequence of UTF-16 encoded characters and the 'length' property simply returns the number of such characters in the string. Surrogates or graphemes are not treated specially for this purpose - they are just represented by the appropriate number of UTF-16 characters.
As each UTF-16 character occupies 2 bytes, it follows that the number of bytes occupied by the string will be twice the length:
fun main() {
val s = "José"
println("The char length is ${s.length}")
println("The byte length is ${Char.SIZE_BYTES * s.length}")
}
- Output:
The char length is 4 The byte length is 8
LabVIEW
Byte Length
LabVIEW is using a special variant of UTF-8, so byte length == character length.
Character Length
Lambdatalk
The lambdatalk {W.length string} function returns the number of bytes in a string. For Unicode characters made of two bytes things are a little bit more tricky. It's easy to add (inline) a new javascript primitive to the dictionary:
{script
LAMBDATALK.DICT["W.unicodeLength"] = function() {
function countCodePoints(str) {
var point,
index,
width = 0,
len = 0;
for (index = 0; index < str.length;) {
point = str.codePointAt(index);
width = 0;
while (point) {
width += 1;
point = point >> 8;
}
index += Math.round(width/2);
len += 1;
}
return len;
}
var args = arguments[0].trim();
return countCodePoints(args)
};
}
Testing:
{W.length Hello, World!} -> 13
{W.length José} -> 4
{W.unicodeLength José} -> 4
{W.length 𝔘𝔫𝔦𝔠𝔬𝔡𝔢} -> 14
{W.unicodeLength 𝔘𝔫𝔦𝔠𝔬𝔡𝔢} -> 7
Lasso
Character Length
'Hello, world!'->size // 13
'møøse'->size // 5
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢'->size // 7
Byte Length
'Hello, world!'->asBytes->size // 13
'møøse'->asBytes->size // 7
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢'->asBytes->size // 28
LFE
Character Length
(length "ASCII text")
10
(length "𝔘𝔫𝔦𝔠𝔬𝔡𝔢 𝔗𝔢𝒙𝔱")
12
> (set encoded (binary ("𝔘𝔫𝔦𝔠𝔬𝔡𝔢 𝔗𝔢𝒙𝔱" utf8)))
#B(240 157 148 152 240 157 148 171 240 157 ...)
> (length (unicode:characters_to_list encoded 'utf8))
12
Byte Length
> (set encoded (binary ("𝔘𝔫𝔦𝔠𝔬𝔡𝔢 𝔗𝔢𝒙𝔱" utf8)))
#B(240 157 148 152 240 157 148 171 240 157 ...)
> (byte_size encoded)
45
> (set bytes (binary ("𝔘𝔫𝔦𝔠𝔬𝔡𝔢 𝔗𝔢𝒙𝔱")))
#B(24 43 38 32 44 33 34 32 23 34 153 49)
> (byte_size bytes)
12
> (set encoded (binary ("ASCII text" utf8)))
#B(65 83 67 73 73 32 116 101 120 116)
> (byte_size encoded)
10
Liberty BASIC
See BASIC
Lingo
Character Length
utf8Str = "Hello world äöü"
put utf8Str.length
-- 15
Byte Length
utf8Str = "Hello world äöü"
put bytearray(utf8Str).length
-- 18
LiveCode
LiveCode fully supports Unicode characters since version 7 ASCII only older Xtalk environments such as Apple's HyperCard did not natively support unicode characters, although being extensible with externals, could possibly have add-on support.
Character Length
put the length of "Hello World"
or
put the number of characters in "Hello World" -- 'chars' short for characters is also valid
or
put length("Hello World")
for Unicode character count use the code units keyword
put the number of codeunits of "Hello World" -- count of unicode characters
Byte Length
Use the 'byte' keyword in LiveCode for an accurate unicode char byte count
put the number of bytes in "Hello World"
Logo
Logo is so old that only ASCII encoding is supported. Modern versions of Logo may have enhanced character set support.
print count "|Hello World| ; 11
print count "møøse ; 5
print char 248 ; ø - implies ISO-Latin character set
LSE64
Byte Length
LSE stores strings as arrays of characters in 64-bit cells plus a count.
" Hello world" @ 1 + 8 * , # 96 = (11+1)*(size of a cell) = 12*8
Character Length
LSE uses counted strings: arrays of characters, where the first cell contains the number of characters in the string.
" Hello world" @ , # 11
Lua
In Lua, a character is always the size of one byte so there is no difference between byte length and character length.
Byte Length
Byte length in UTF-8:
str = "Hello world"
length = #str
or
str = "Hello world"
length = string.len(str)
Character Length
Only valid for ASCII:
str = "Hello world"
length = #str
or
str = "Hello world"
length = string.len(str)
For Unicode string, use utf8 module:
utf8.len("møøse")
utf8.len("𝔘𝔫𝔦𝔠𝔬𝔡𝔢")
utf8.len("J̲o̲s̲é̲")
- Output:
5 7 8
M2000 Interpreter
module String_length {
A$=format$("J\u0332o\u0332s\u0332e\u0301\u0332")
Print Len(A$) = 9 ' true Utf-16LE
Print Len.Disp(A$) = 4 \\ display length
Buffer Clear Mem as Byte*100
\\ Write at memory at offset 0 or address Mem(0)
Return Mem, 0:=A$
Print Eval$(Mem, 0, 18)
For i=0 to 17 step 2
\\ print hex value and character
Hex Eval(Mem, i as integer), ChrCode$(Eval(Mem, i as integer))
Next i
Document B$=A$
\\ encode to utf-8 with BOM (3 bytes 0xEF,0xBB,0xBF)
Save.Doc B$, "Checklen.doc", 2
Print Filelen("Checklen.doc")=17
\\ So length is 14 bytes + 3 the BOM
Mem=Buffer("Checklen.doc")
Print len(Mem)=17 // len works for buffers too - unit byte
// version 12 can handle strings without suffix $
C=eval$(mem, 3, 14) // from 4th byte get 14 bytes in a string
Print len(C)*2=14 ' bytes // len()) for strings return double type of words (can return 0.5)
C=string$(C as utf8dec) ' decode bytes from utf8 to utf16LE
Print len(C)=9, C=A$, Len.Disp(C)=4
Print C
Report 2, C // proportional print on console - for text center justified rendering (2 - center)
}
String_length
Maple
Character length
length("Hello world");
Byte count
nops(convert("Hello world",bytes));
Mathematica /Wolfram Language
Character length
StringLength["Hello world"]
Byte length
StringByteCount["Hello world"]
MATLAB
Character Length
>> length('møøse')
ans =
5
Byte Length
MATLAB apparently encodes strings using UTF-16.
>> numel(dec2hex('møøse'))
ans =
10
Maxima
s: "the quick brown fox jumps over the lazy dog";
slength(s);
/* 43 */
MAXScript
Character Length
"Hello world".count
Mercury
Mercury's C and Erlang backends use UTF-8 encoded strings; the Java and C# backends using the underlying UTF-16 encoding of those languages. The function string.length/1 returns the number of code units in a string in target language encoding. The function string.count_utf8_code_units/1 returns the number of UTF-8 code units in a string regardless of the target language.
Byte Length
:- module string_byte_length.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- import_module list, string.
main(!IO) :-
Words = ["møøse", "𝔘𝔫𝔦𝔠𝔬𝔡𝔢", "J\x332\o\x332\s\x332\e\x301\\x332\"],
io.write_list(Words, "", write_length, !IO).
:- pred write_length(string::in, io::di, io::uo) is det.
write_length(String, !IO):-
NumBytes = count_utf8_code_units(String),
io.format("%s: %d bytes\n", [s(String), i(NumBytes)], !IO).
Output:
møøse: 7 bytes 𝔘𝔫𝔦𝔠𝔬𝔡𝔢: 28 bytes J̲o̲s̲é̲: 14 bytes
Character Length
The function string.count_codepoints/1 returns the number of code points in a string.
:- module string_character_length.
:- interface.
:- import_module io.
:- pred main(io::di, io::uo) is det.
:- implementation.
:- import_module list, string.
main(!IO) :-
Words = ["møøse", "𝔘𝔫𝔦𝔠𝔬𝔡𝔢", "J\x332\o\x332\s\x332\e\x301\\x332\"],
io.write_list(Words, "", write_length, !IO).
:- pred write_length(string::in, io::di, io::uo) is det.
write_length(String, !IO) :-
NumChars = count_codepoints(String),
io.format("%s: %d characters\n", [s(String), i(NumChars)], !IO).
Output:
møøse: 5 characters 𝔘𝔫𝔦𝔠𝔬𝔡𝔢: 7 characters J̲o̲s̲é̲: 9 characters
Metafont
Metafont has no way of handling properly encodings different from ASCII. So it is able to count only the number of bytes in a string.
string s;
s := "Hello Moose";
show length(s); % 11 (ok)
s := "Hello Møøse";
show length(s); % 13 (number of bytes when the string is UTF-8 encoded,
% since ø takes two bytes)
Note: in the lang tag, Møøse is Latin1-reencoded, showing up two bytes (as Latin1) instead of one
MIPS Assembly
This only supports ASCII encoding, so it'll return both byte length and char length.
.data
#.asciiz automatically adds the NULL terminator character, \0 for us.
string: .asciiz "Nice string you got there!"
.text
main:
la $a1,string #load the beginning address of the string.
loop:
lb $a2,($a1) #load byte (i.e. the char) at $a1 into $a2
addi $a1,$a1,1 #increment $a1
beqz $a2,exit_procedure #see if we've hit the NULL char yet
addi $a0,$a0,1 #increment counter
j loop #back to start
exit_procedure:
li $v0,1 #set syscall to print integer
syscall
li $v0,10 #set syscall to cleanly exit EXIT_SUCCESS
syscall
mIRC Scripting Language
Byte Length
alias stringlength { echo -a Your Name is: $len($$?="Whats your name") letters long! }
Character Length
$utfdecode() converts an UTF-8 string to the locale encoding, with unrepresentable characters as question marks. Since mIRC is not yet fully Unicode aware, entering Unicode text trough a dialog box will automatically convert it to ASCII.
alias utf8len { return $len($utfdecode($1)) }
alias stringlength2 {
var %name = Børje
echo -a %name is: $utf8len(%name) characters long!
}
Modula-3
Byte Length
MODULE ByteLength EXPORTS Main;
IMPORT IO, Fmt, Text;
VAR s: TEXT := "Foo bar baz";
BEGIN
IO.Put("Byte length of s: " & Fmt.Int((Text.Length(s) * BYTESIZE(s))) & "\n");
END ByteLength.
Character Length
MODULE StringLength EXPORTS Main;
IMPORT IO, Fmt, Text;
VAR s: TEXT := "Foo bar baz";
BEGIN
IO.Put("String length of s: " & Fmt.Int(Text.Length(s)) & "\n");
END StringLength.
Nemerle
Both examples rely on .Net faculties, so they're almost identical to C#
Character Length
def message = "How long am I anyways?";
def charlength = message.Length;
Byte Length
using System.Text;
def message = "How long am I anyways?";
def bytelength = Encoding.Unicode.GetByteCount(message);
NewLISP
Character Length
(set 'Str "møøse")
(println Str " is " (length Str) " characters long")
Nim
Byte Length
echo "møøse".len # 7
echo "𝔘𝔫𝔦𝔠𝔬𝔡𝔢".len # 28
echo "J̲o̲s̲é̲".len # 13
Character Length
import unicode
echo "møøse".runeLen # 5
echo "𝔘𝔫𝔦𝔠𝔬𝔡𝔢".runeLen # 7
echo "J̲o̲s̲é̲".runeLen # 8
Grapheme Length
graphemeLen() does not do what you expect. It doesn't return the number of grapheme in a string but returns the number of bytes at a character/codepoint index for a given string.
Oberon-2
Byte Length
MODULE Size;
IMPORT Out;
VAR s: LONGINT;
string: ARRAY 5 OF CHAR;
BEGIN
string := "Foo";
s := LEN(string);
Out.String("Size: ");
Out.LongInt(s,0);
Out.Ln;
END Size.
Output:
Size: 5
Character Length
MODULE Length;
IMPORT Out, Strings;
VAR l: INTEGER;
string: ARRAY 5 OF CHAR;
BEGIN
string := "Foo";
l := Strings.Length(string);
Out.String("Length: ");
Out.Int(l,0);
Out.Ln;
END Length.
Output:
Length: 3
Objeck
All character string elements are 1-byte in size therefore a string's byte size and length are the same.
Character Length
"Foo"->Size()->PrintLine();
Byte Length
"Foo"->Size()->PrintLine();
Objective-C
In order to be not ambiguous about the encoding used in the string, we explicitly provide it in UTF-8 encoding. The string is "møøse" (ø UTF-8 encoded is in hexadecimal C3 B8).
Character Length
Objective-C encodes strings in UTF-16, which represents each character (code point) with one or two 16-bit code units. This is a variable-length encoding scheme. The most commonly used characters are represented by one 16-bit code unit, while "supplementary characters" are represented by two (called a "surrogate pair").
The length method of NSString objects is not the length of that string in characters. Instead, it only gives the number of 16-bit code units used to encode a string. This is not (always) the number of Unicode characters (code points) in the string.
// Return the length in characters
// XXX: does not (always) count Unicode characters (code points)!
unsigned int numberOfCharacters = [@"møøse" length]; // 5
Since Mac OS X 10.6, CFString has methods for converting between supplementary characters and surrogate pair. However, the easiest way to get the number of characters is probably to encode it in UTF-32 (which is a fixed-length encoding) and divide by 4:
int realCharacterCount = [s lengthOfBytesUsingEncoding: NSUTF32StringEncoding] / 4;
Byte Length
Objective-C encodes strings in UTF-16, which represents each character with one or two 16-bit values. The length method of NSString objects returns the number of 16-bit values used to encode a string, so the number of bytes can be determined by doubling that number.
int byteCount = [@"møøse" length] * 2; // 10
Another way to know the byte length of a string is to explicitly specify the charset we desire.
// Return the number of bytes depending on the encoding,
// here explicitly UTF-8
unsigned numberOfBytes =
[@"møøse" lengthOfBytesUsingEncoding: NSUTF8StringEncoding]; // 7
OCaml
In OCaml currently, characters inside the standard type string are bytes, and a single character taken alone has the same binary representation as the OCaml int (which is equivalent to a C long) which is a machine word.
For internationalization there is Camomile, a comprehensive Unicode library for OCaml. Camomile provides Unicode character type, UTF-8, UTF-16, and more...
Byte Length
Standard OCaml strings are classic ASCII ISO 8859-1, so the function String.length returns the byte length which is the character length in this encoding:
String.length "Hello world" ;;
Character Length
While using the UTF8 module of Camomile the byte length of an utf8 encoded string will be get with String.length and the character length will be returned by UTF8.length:
open CamomileLibrary
let () =
Printf.printf " %d\n" (String.length "møøse");
Printf.printf " %d\n" (UTF8.length "møøse");
;;
Run this code with the command:
$ ocaml bigarray.cma -I $(ocamlfind query camomile)/library/ camomileLibrary.cma strlen.ml 7 5
Alternatively, you can use the UChar module (available since OCaml 4.03) to do it without additional modules.
let utf8_length (s: String.t) =
let byte_length = String.length s in
let rec count acc n =
if n = byte_length
then acc
else
let n' = n + (String.get_utf_8_uchar s n |> Uchar.utf_decode_length) in
count (succ acc) n'
in
count 0 0
;;
# utf8_length "møøse" - : int = 5
Octave
s = "string";
stringlen = length(s)
This gives the number of bytes, not of characters. e.g. length("è") is 2 when "è" is encoded e.g. as UTF-8.
Oforth
Oforth strings are UTF8 encoded.
size method returns number of UTF8 characters into a string
basicSize method returns number of bytes into a string
Ol
; Character length
(print (string-length "Hello, wørld!"))
; ==> 13
; Byte (utf-8 encoded) length
(print (length (string->bytes "Hello, wørld!")))
; ==> 14
OpenEdge/Progress
The codepage can be set independently for input / output and internal operations. The following examples are started from an iso8859-1 session and therefore need to use fix-codepage to adjust the string to utf-8.
Character Length
DEF VAR lcc AS LONGCHAR.
FIX-CODEPAGE( lcc ) = "UTF-8".
lcc = "møøse".
MESSAGE LENGTH( lcc ) VIEW-AS ALERT-BOX.
Byte Length
DEF VAR lcc AS LONGCHAR.
FIX-CODEPAGE( lcc ) = "UTF-8".
lcc = "møøse".
MESSAGE LENGTH( lcc, "RAW" ) VIEW-AS ALERT-BOX.
Oz
Byte Length
{Show {Length "Hello World"}}
Oz uses a single-byte encoding by default. So for normal strings, this will also show the correct character length.
PARI/GP
Character Length
Characters = bytes in Pari; the underlying strings are C strings interpreted as US-ASCII.
len(s)=#s; \\ Alternately, len(s)=length(s); or even len=length;
Byte Length
This works on objects of any sort, not just strings, and includes overhead.
len(s)=sizebyte(s);
Pascal
Byte Length
const
s = 'abcdef';
begin
writeln (length(s))
end.
Output:
6
PascalABC.NET
##
var s := 'møøse';
// Byte Length
Print(s.Length);
// Character Length
Print(System.Text.Encoding.Utf8.GetByteCount(s));
- Output:
5 7
Perl
Byte Length
Strings in Perl consist of characters. Measuring the byte length therefore requires conversion to some binary representation (called encoding, both noun and verb).
use utf8; # so we can use literal characters like ☺ in source
use Encode qw(encode);
print length encode 'UTF-8', "Hello, world! ☺";
# 17. The last character takes 3 bytes, the others 1 byte each.
print length encode 'UTF-16', "Hello, world! ☺";
# 32. 2 bytes for the BOM, then 15 byte pairs for each character.
Character Length
my $length = length "Hello, world!";
Grapheme Length
Since Perl 5.12, /\X/
matches an extended grapheme cluster. See "Unicode overhaul" in perl5120delta and also UAX #29.
Perl understands that "\x{1112}\x{1161}\x{11ab}\x{1100}\x{1173}\x{11af}" (한글) contains 2 graphemes, just like "\x{d55c}\x{ae00}" (한글). The longer string uses Korean combining jamo characters.
use v5.12;
my $string = "\x{1112}\x{1161}\x{11ab}\x{1100}\x{1173}\x{11af}"; # 한글
my $len;
$len++ while ($string =~ /\X/g);
printf "Grapheme length: %d\n", $len;
- Output:
Grapheme length: 2
Phix
The standard length function returns the number of bytes, character length is achieved by converting to utf32
constant s = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" ?length(s) ?length(utf8_to_utf32(s))
- Output:
28 7
PHP
Program in a UTF8 linux:
<?php
foreach (array('møøse', '𝔘𝔫𝔦𝔠𝔬𝔡𝔢', 'J̲o̲s̲é̲') as $s1) {
printf('String "%s" measured with strlen: %d mb_strlen: %s grapheme_strlen %s%s',
$s1, strlen($s1),mb_strlen($s1), grapheme_strlen($s1), PHP_EOL);
}
yields the result:
String "møøse" measured with strlen: 7 mb_strlen: 7 grapheme_strlen 5 String "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" measured with strlen: 28 mb_strlen: 28 grapheme_strlen 7 String "J̲o̲s̲é̲" measured with strlen: 13 mb_strlen: 13 grapheme_strlen 4
PicoLisp
(let Str "møøse"
(prinl "Character Length of \"" Str "\" is " (length Str))
(prinl "Byte Length of \"" Str "\" is " (size Str)) )
Output:
Character Length of "møøse" is 5 Byte Length of "møøse" is 7 -> 7
PL/I
declare WS widechar (13) initial ('Hello world.');
put ('Character length=', length (WS));
put skip list ('Byte length=', size(WS));
declare SM graphic (13) initial ('Hello world');
put ('Character length=', length(SM));
put skip list ('Byte length=', size(trim(SM)));
PL/SQL
LENGTH calculates length using characters as defined by the input character set. LENGTHB uses bytes instead of characters. LENGTHC uses Unicode complete characters. LENGTH2 uses UCS2 code points. LENGTH4 uses UCS4 code points.
Byte Length
DECLARE
string VARCHAR2(50) := 'Hello, world!';
stringlength NUMBER;
BEGIN
stringlength := LENGTHB(string);
END;
Character Length
DECLARE
string VARCHAR2(50) := 'Hello, world!';
stringlength NUMBER;
unicodelength NUMBER;
ucs2length NUMBER;
ucs4length NUMBER;
BEGIN
stringlength := LENGTH(string);
unicodelength := LENGTHC(string);
ucs2length := LENGTH2(string);
ucs4length := LENGTH4(string);
END;
Plain English
Byte Length
Plain English does not handle Unicode, so strings return their length in bytes.
To run:
Start up.
Put "møøse" into a string.
Write the string's length to the output.
Wait for the escape key.
Shut down.
Pop11
Byte Length
Currently Pop11 supports only strings consisting of 1-byte units. Strings can carry arbitrary binary data, so user can for example use UTF-8 (however builtin procedures will treat each byte as a single character). The length function for strings returns length in bytes:
lvars str = 'Hello, world!';
lvars len = length(str);
PostScript
Character Length
(Hello World) length =
11
Potion
Character Length
"møøse" length print
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢" length print
"J̲o̲s̲é̲" length print
PowerShell
Character Length
$s = "Hëlló Wørłð"
$s.Length
Byte Length
For UTF-16, which is the default in .NET and therefore PowerShell:
$s = "Hëlló Wørłð"
[System.Text.Encoding]::Unicode.GetByteCount($s)
For UTF-8:
[System.Text.Encoding]::UTF8.GetByteCount($s)
PureBasic
Character Length
a = Len("Hello World") ;a will be 11
Byte Length
Returns the number of bytes required to store the string in memory in the given format in bytes. 'Format' can be #PB_Ascii, #PB_UTF8 or #PB_Unicode. PureBasic code can be compiled using either Unicode (2-byte) or Ascii (1-byte) encodings for strings. If 'Format' is not specified, the mode of the executable (unicode or ascii) is used.
Note: The number of bytes returned does not include the terminating Null-Character of the string. The size of the Null-Character is 1 byte for Ascii and UTF8 mode and 2 bytes for Unicode mode.
a = StringByteLength("ä", #PB_UTF8) ;a will be 2
b = StringByteLength("ä", #PB_Ascii) ;b will be 1
c = StringByteLength("ä", #PB_Unicode) ;c will be 2
Python
2.x
In Python 2.x, there are two types of strings: regular (8-bit) strings, and Unicode strings. Unicode string literals are prefixed with "u".
Byte Length
For 8-bit strings, the byte length is the same as the character length:
print len('ascii')
# 5
For Unicode strings, length depends on the internal encoding. Since version 2.2 Python shipped with two build options: it either uses 2 or 4 bytes per character. The internal representation is not interesting for the user.
# The letter Alef
print len(u'\u05d0'.encode('utf-8'))
# 2
print len(u'\u05d0'.encode('iso-8859-8'))
# 1
Example from the problem statement:
#!/bin/env python
# -*- coding: UTF-8 -*-
s = u"møøse"
assert len(s) == 5
assert len(s.encode('UTF-8')) == 7
assert len(s.encode('UTF-16-BE')) == 10 # There are 3 different UTF-16 encodings: LE and BE are little endian and big endian respectively, the third one (without suffix) adds 2 extra leading bytes: the byte-order mark (BOM).
Character Length
len() returns the number of code units (not code points!) in a Unicode string or plain ASCII string. On a wide build, this is the same as the number of code points, but on a narrow one it is not. Most linux distributions install the wide build by default, you can check the build at runtime with:
import sys
sys.maxunicode # 1114111 on a wide build, 65535 on a narrow build
To get the length of encoded string, you have to decode it first:
print len('ascii')
# 5
print len(u'\u05d0') # the letter Alef as unicode literal
# 1
print len('\xd7\x90'.decode('utf-8')) # Same encoded as utf-8 string
# 1
print hex(sys.maxunicode), len(unichr(0x1F4A9))
# ('0x10ffff', 1)
On a narrow build, len() gives the wrong answer for non-BMP chars
print hex(sys.maxunicode), len(unichr(0x1F4A9))
# ('0xffff', 2)
3.x
In Python 3.x, strings are Unicode strings and a bytes type if available for storing an immutable sequence of bytes (there's also available a bytearray type, which is mutable)
Byte Length
You can use len() to get the length of a byte sequence.
print(len(b'Hello, World!'))
# 13
To get a byte sequence from a string, you have to encode it with the desired encoding:
# The letter Alef
print(len('\u05d0'.encode())) # the default encoding is utf-8 in Python3
# 2
print(len('\u05d0'.encode('iso-8859-8')))
# 1
Example from the problem statement:
#!/bin/env python
# -*- coding: UTF-8 -*-
s = "møøse"
assert len(s) == 5
assert len(s.encode('UTF-8')) == 7
assert len(s.encode('UTF-16-BE')) == 10 # There are 3 different UTF-16 encodings: LE and BE are little endian and big endian respectively, the third one (without suffix) adds 2 extra leading bytes: the byte-order mark (BOM).
u="𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
assert len(u.encode()) == 28
assert len(u.encode('UTF-16-BE')) == 28
Character Length
Since Python3.3 the internal storage of unicode strings has been optimized: strings that don't contain characters outside the latin-1 set, are stored with 8 bits for each character, strings that don't contain codepoints outside the BMP (lone surrogates aren't allowed) are stored as UCS-2, while all the others use UCS-4.
Thus Python is able to avoid memory overhead when dealing with only ASCII strings, while handling correctly all codepoints in Unicode. len() returns the number of characters/codepoints:
print(len("𝔘𝔫𝔦𝔠𝔬𝔡𝔢"))
# 7
Until Python 3.2 instead, length depended on the internal encoding, since it shipped with two build options: it either used 2 or 4 bytes per character.
len() returned the number of code units in a string, which could be different from the number of characters. In a narrow build, this is not a reliable way to get the number of characters. You can only easily count code points in a wide build. Most linux distributions install the wide build by default, you can check the build at runtime with:
import sys
sys.maxunicode # 1114111 on a wide build, 65535 on a narrow build
print(len('ascii'))
# 5
print(len('\u05d0')) # the letter Alef as unicode literal
# 1
To get the length of an encoded byte sequence, you have to decode it first:
print(len(b'\xd7\x90'.decode('utf-8'))) # Alef encoded as utf-8 byte sequence
# 1
print(hex(sys.maxunicode), len(unichr(0x1F4A9)))
# ('0x10ffff', 1)
On a narrow build, len() gives the wrong answer for non-BMP chars
print(hex(sys.maxunicode), len(unichr(0x1F4A9)))
# ('0xffff', 2)
R
Byte length
a <- "m\u00f8\u00f8se"
print(nchar(a, type="bytes")) # print 7
Character length
print(nchar(a, type="chars")) # print 5
Racket
Using this definition:
(define str "J\u0332o\u0332s\u0332e\u0301\u0332")
on the REPL, we get the following:
Character length
-> (printf "str has ~a characters" (string-length str))
str has 9 characters
Byte length
-> (printf "str has ~a bytes in utf-8" (bytes-length (string->bytes/utf-8 str)))
str has 14 bytes in utf-8
Raku
(formerly Perl 6)
Byte Length
say 'møøse'.encode('UTF-8').bytes;
Character Length
say 'møøse'.codes;
Grapheme Length
say 'møøse'.chars;
REBOL
Rebol 2 does not natively support UCS (Unicode), so character and byte length are the same. See utf-8.r for an external UTF-8 library.
Rebol 3 natively supports UTF-8.
Byte Length
;; r2
length? "møøse"
;; r3
length? to-binary "møøse"
Character length
;; r3
length? "møøse"
ReScript
Byte Length
Js.String2.length("abcd") == 4
Retro
Byte Length
'møøse s:length n:put
Character Length
Retro does not have built-in support for Unicode, but counting of characters can be done with a small amount of effort.
chain: UTF8'
{{
: utf+ ( $-$ )
[ 1+ dup @ %11000000 and %10000000 = ] while ;
: count ( $-$ )
0 !here
repeat dup @ 0; drop utf+ here ++ again ;
---reveal---
: getLength ( $-n )
count drop @here ;
}}
;chain
"møøse" ^UTF8'getLength putn
REXX
Classic REXX don't support Unicodes, so character and byte length are the same.
All characters (in strings) are stored as 8-bit bytes. Indeed, everything in REXX
is stored as character strings.
Byte Length
/*REXX program displays the lengths (in bytes/characters) for various strings. */
/* 1 */ /*a handy-dandy over/under scale.*/
/* 123456789012345 */
hello = 'Hello, world!' ; say 'the length of HELLO is ' length(hello)
happy = 'Hello, world! ☺' ; say 'the length of HAPPY is ' length(happy)
jose = 'José' ; say 'the length of JOSE is ' length(jose)
nill = '' ; say 'the length of NILL is ' length(nill)
null = ; say 'the length of NULL is ' length(null)
sum = 5+1 ; say 'the length of SUM is ' length(sum)
/* [↑] is, of course, 6. */
/*stick a fork in it, we're done.*/
output
length of HELLO is 13 length of HAPPY is 15 length of JOSE is 4 length of NILL is 0 length of NULL is 0 length of SUM is 1
Ring
Character Length
aString = "Welcome to the Ring Programming Language"
aStringSize = len(aString)
see "Character lenghts : " + aStringSize
Robotic
Character Length
set "$local1" to "Hello world!"
* "String length: &$local1.length&"
end
Unfortunately, only character length can be retrieved in this language.
RPL
RPL strings are all made of 8-bit characters.
"RPL" SIZE
Ruby
UTF8 is the default encoding in Ruby.
Byte Length
"J̲o̲s̲é̲".bytesize
Character Length
"J̲o̲s̲é̲".chars.length
Grapheme Length
"J̲o̲s̲é̲".grapheme_clusters.length
Code Set Independence
The next examples show the byte length and character length of "møøse" in different encodings.
To run these programs, you must convert them to different encodings.
- If you use Emacs: Paste each program into Emacs. The magic comment, like
-*- coding: iso-8859-1 -*-
, will tell Emacs to save with that encoding.- If your text editor saves UTF-8: Convert the file before running it. For example:
$ ruby -pe '$_.encode!("iso-8859-1", "utf-8")' scratch.rb | ruby
Program | Output |
---|---|
# -*- coding: iso-8859-1 -*-
s = "møøse"
puts "Byte length: %d" % s.bytesize
puts "Character length: %d" % s.length |
Byte length: 5 Character length: 5 |
# -*- coding: utf-8 -*-
s = "møøse"
puts "Byte length: %d" % s.bytesize
puts "Character length: %d" % s.length |
Byte length: 7 Character length: 5 |
# -*- coding: gb18030 -*-
s = "møøse"
puts "Byte length: %d" % s.bytesize
puts "Character length: %d" % s.length |
Byte length: 11 Character length: 5 |
Ruby 1.8
The next example works with both Ruby 1.8 and Ruby 1.9. In Ruby 1.8, the strings have no encodings, and String#length is the byte length. In Ruby 1.8, the regular expressions knows three Japanese encodings.
/./n
uses no multibyte encoding././e
uses EUC-JP././s
uses Shift-JIS or Windows-31J././u
uses UTF-8.
Then either string.scan(/./u).size
or string.gsub(/./u, ' ').size
counts the UTF-8 characters in string.
# -*- coding: utf-8 -*-
class String
# Define String#bytesize for Ruby 1.8.6.
unless method_defined?(:bytesize)
alias bytesize length
end
end
s = "文字化け"
puts "Byte length: %d" % s.bytesize
puts "Character length: %d" % s.gsub(/./u, ' ').size
Run BASIC
input a$
print len(a$)
Rust
Byte Length
fn main() {
let s = "文字化け"; // UTF-8
println!("Byte Length: {}", s.len());
}
Character Length
fn main() {
let s = "文字化け"; // UTF-8
println!("Character length: {}", s.chars().count());
}
SAS
data _null_;
a="Hello, World!";
b=length(c);
put _all_;
run;
Scala
object StringLength extends App {
val s1 = "møøse"
val s3 = List("\uD835\uDD18", "\uD835\uDD2B", "\uD835\uDD26",
"\uD835\uDD20", "\uD835\uDD2C", "\uD835\uDD21", "\uD835\uDD22").mkString
val s4 = "J\u0332o\u0332s\u0332e\u0301\u0332"
List(s1, s3, s4).foreach(s => println(
s"The string: $s, characterlength= ${s.length} UTF8bytes= ${
s.getBytes("UTF-8").size
} UTF16bytes= ${s.getBytes("UTF-16LE").size}"))
}
- Output:
The string: møøse, characterlength= 5 UTF8bytes= 7 UTF16bytes= 10 The string: 𝔘𝔫𝔦𝔠𝔬𝔡𝔢, characterlength= 14 UTF8bytes= 28 UTF16bytes= 28 The string: J̲o̲s̲é̲, characterlength= 9 UTF8bytes= 14 UTF16bytes= 18
Scheme
Byte Length
string-size function is only Gauche function.
(string-size "Hello world")
(bytes-length #"Hello world")
Character Length
string-length function is in R5RS, R6RS.
(string-length "Hello world")
sed
Character Length
Sed breaks strings on newline characters, and doesn't include them in the count.
Text is read from standard input e.g. echo "string" | sed -f script.sed
or sed -f script.sed file.txt
(The solution given would be the contents of a text file script.sed
in these cases).
For files with more than one line, sed will give a count for each line.
# create unary numeral (i = 1)
s/./i/g
:loop
# divide by 10 (x = 10)
s/i\{10\}/x/g
# convert remainder to decimal digit
/i/!s/[0-9]*$/0&/
s/i\{9\}/9/
s/i\{8\}/8/
s/i\{7\}/7/
s/i\{6\}/6/
s/iiiii/5/
s/iiii/4/
s/iii/3/
s/ii/2/
s/i/1/
# convert quotient (10s) to 1s
y/x/i/
# start over for the next magnitude (if any)
/i/b loop
Seed7
Character Length
length("Hello, world!")
SETL
Character Length
print(# "Hello, world!"); -- '#' is the cardinality operator. Works on strings, tuples, and sets.
Sidef
var str = "J\x{332}o\x{332}s\x{332}e\x{301}\x{332}";
Byte Length
UTF-8 byte length (default):
say str.bytes.len; #=> 14
UTF-16 byte length:
say str.encode('UTF-16').bytes.len; #=> 20
Character Length
say str.chars.len; #=> 9
Grapheme Length
say str.graphs.len; #=> 4
Simula
Simula has no bultin support for character encodings (Unicode was not even invented in the year 1967). The encoding was regarded responsibility of the operating system and one byte must match one character. So character constants encoded in UTF-8 are not possible. But reading from a utf8-encoded input file is actually possible.
- Input:
møøse 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 J̲o̲s̲é̲ €
Byte Length
BEGIN
TEXT LINE;
WHILE NOT LASTITEM DO
BEGIN
INTEGER L;
LINE :- COPY(SYSIN.IMAGE).STRIP;
OUTCHAR('"');
OUTTEXT(LINE);
OUTCHAR('"');
OUTTEXT(" BYTE LENGTH = "); OUTINT(LINE.LENGTH, 0);
OUTIMAGE;
INIMAGE;
END;
END.
- Output:
"møøse" BYTE LENGTH = 7 "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" BYTE LENGTH = 28 "J̲o̲s̲é̲" BYTE LENGTH = 13 "€" BYTE LENGTH = 3
Character Length
To calculate the character length, one can do it manually:
BEGIN
! NUMBER OF UFT8 CHARACTERS IN STRING ;
INTEGER PROCEDURE UTF8STRLEN(S); TEXT S;
BEGIN
INTEGER R, LEN, BYTES, ALLBYTES;
CHARACTER BYTE;
WHILE S.MORE DO
BEGIN
BYTE := S.GETCHAR;
ALLBYTES := ALLBYTES + 1;
R := RANK(BYTE);
LEN := LEN + 1;
BYTES :=
IF R >= 0 AND R <= 127 THEN 1 ELSE ! 0....... ASCII ;
IF R >= 128 AND R <= 191 THEN 0 ELSE ! 10...... CONTINUATION ;
IF R >= 192 AND R <= 223 THEN 2 ELSE ! 110..... 10x ;
IF R >= 224 AND R <= 239 THEN 3 ELSE ! 1110.... 10x 10x ;
IF R >= 240 AND R <= 247 THEN 4 ELSE ! 11110... 10x 10x 10x ;
-1;
IF BYTES = -1 THEN ERROR("ILLEGAL UTF8 STRING");
WHILE BYTES > 1 DO
BEGIN
BYTE := S.GETCHAR;
ALLBYTES := ALLBYTES + 1;
BYTES := BYTES - 1;
END;
END;
UTF8STRLEN := LEN;
END UTF8STRLEN;
TEXT LINE;
WHILE NOT LASTITEM DO
BEGIN
INTEGER L;
LINE :- COPY(SYSIN.IMAGE).STRIP;
OUTCHAR('"');
OUTTEXT(LINE);
OUTCHAR('"');
L := UTF8STRLEN(LINE);
OUTTEXT(" CHARACTER LENGTH = "); OUTINT(UTF8STRLEN(LINE), 0);
OUTIMAGE;
INIMAGE;
END;
END.
- Output:
"møøse" CHARACTER LENGTH = 5 "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" CHARACTER LENGTH = 7 "J̲o̲s̲é̲" CHARACTER LENGTH = 8 "€" CHARACTER LENGTH = 1
Slate
'Hello, world!' length.
Slope
Character Length
(length "møøse")
Byte Lenth
(length (string->bytes "møøse"))
Smalltalk
Internally, Smalltalk represents strings as a collection of characters, with each character representing a single code point. To get at/from bytes, the strings must be en/decoded and converted to/from a byte array. UTFX is only used when communicating with the external world (files/sockets etc.)
'hello' size -> 5
'hello' utf8Encoded size -> 5
'hello' utf8Encoded asByteArray -> #[104 101 108 108 111]
#[104 101 108 108 111] asString -: 'hello'
'møøse' size -> 5
'møøse' utf8Encoded size -> 7
'møøse' utf8Encoded asByteArray -> #[109 195 184 195 184 115 101]
#[109 195 184 195 184 115 101] utf8Decoded ->'møøse'
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢' size -> 7
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢' utf8Encoded size -> 28
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢' utf8Encoded asByteArray -> #[240 157 148 152 240 157 148 171 240 157 148 166 240 157 148 160 240 157 148 172 240 157 148 161 240 157 148 162]
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢' utf16Encoded size -> 14
'𝔘𝔫𝔦𝔠𝔬𝔡𝔢' utf8Encoded asWordArray -> WordArray(55349 56600 55349 56619 55349 56614 55349 56608 55349 56620 55349 56609 55349 56610)
Byte Length
string := 'Hello, world!'.
string size.
Character Length
string := 'Hello, world!'.
string numberOfCharacters.
requires loading the Iconv package:
PackageLoader fileInPackage: 'Iconv'
SNOBOL4
Byte Length
output = "Byte length: " size(trim(input))
end
Character Length
The example works AFAIK only with CSnobol4 by Phil Budne
-include "utf.sno"
output = "Char length: " utfsize(trim(input))
end
Sparkling
Byte length
spn:1> sizeof "Hello, wørld!"
= 14
SPL
Byte Length
All strings in SPL are Unicode. See code below.
Character Length
t = ["abc","J̲o̲s̲é̲","møøse","𝔘𝔫𝔦𝔠𝔬𝔡𝔢"]
> i, 1..#.size(t,1)
? i>1, #.output()
#.output(#.quot,t[i],#.quot," contains")
p = #.split(t[i])
cn = #.size(p,1)
s = #.str(cn,">3>")+" chars: "
> j, 1..cn
? j>1, s += ", "
s += p[j]
<
#.output(s)
q = #.array(t[i])
bn = #.size(q,1)
s = #.str(bn,">3>")+" bytes: "
> j, 1..bn
? j>1, s += ", "
s += #.str(q[j],"X2")+"h"
<
#.output(s)
<
- Output:
"abc" contains 3 chars: a,b,c 6 bytes: 61h, 00h, 62h, 00h, 63h, 00h "J̲o̲s̲é̲" contains 4 chars: J̲,o̲,s̲,é̲ 16 bytes: 4Ah, 00h, 32h, 03h, 6Fh, 00h, 32h, 03h, 73h, 00h, 32h, 03h, E9h, 00h, 32h, 03h "møøse" contains 5 chars: m,ø,ø,s,e 10 bytes: 6Dh, 00h, F8h, 00h, F8h, 00h, 73h, 00h, 65h, 00h "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" contains 7 chars: 𝔘,𝔫,𝔦,𝔠,𝔬,𝔡,𝔢 28 bytes: 35h, D8h, 18h, DDh, 35h, D8h, 2Bh, DDh, 35h, D8h, 26h, DDh, 35h, D8h, 20h, DDh, 35h, D8h, 2Ch, DDh, 35h, D8h, 21h, DDh, 35h, D8h, 22h, DDh
Grapheme Length
SPL treats grapheme as a single character when splitting text. See code above.
SQL
Byte length
SELECT LENGTH(CAST('møøse' AS BLOB));
Character length
SELECT LENGTH('møøse');
SQL PL
Character Length
With SQL only:
VALUES LENGTH('møøse', CODEUNITS16);
VALUES LENGTH('møøse', CODEUNITS32);
VALUES CHARACTER_LENGTH('møøse', CODEUNITS32);
VALUES LENGTH2('møøse');
VALUES LENGTH4('møøse');
VALUES LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢', CODEUNITS16);
VALUES LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢', CODEUNITS32);
VALUES CHARACTER_LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢', CODEUNITS32);
VALUES LENGTH2('𝔘𝔫𝔦𝔠𝔬𝔡𝔢');
VALUES LENGTH4('𝔘𝔫𝔦𝔠𝔬𝔡𝔢');
VALUES LENGTH('J̲o̲s̲é̲', CODEUNITS16);
VALUES LENGTH('J̲o̲s̲é̲', CODEUNITS32);
VALUES CHARACTER_LENGTH('J̲o̲s̲é̲', CODEUNITS32);
VALUES LENGTH2('J̲o̲s̲é̲');
VALUES LENGTH4('J̲o̲s̲é̲');
Output:
db2 -t db2 => VALUES LENGTH('møøse', CODEUNITS16); 1 ----------- 5 1 record(s) selected. db2 => VALUES LENGTH('møøse', CODEUNITS32); 1 ----------- 5 1 record(s) selected. db2 => VALUES CHARACTER_LENGTH('møøse', CODEUNITS32); 1 ----------- 5 1 record(s) selected. db2 => VALUES LENGTH2('møøse'); 1 ----------- 5 1 record(s) selected. db2 => VALUES LENGTH4('møøse'); 1 ----------- 5 1 record(s) selected. db2 => VALUES LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢', CODEUNITS16); 1 ----------- 14 1 record(s) selected. db2 => VALUES LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢', CODEUNITS32); 1 ----------- 7 1 record(s) selected. db2 => VALUES CHARACTER_LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢', CODEUNITS32); 1 ----------- 7 1 record(s) selected. db2 => VALUES LENGTH2('𝔘𝔫𝔦𝔠𝔬𝔡𝔢'); 1 ----------- 14 1 record(s) selected. db2 => VALUES LENGTH4('𝔘𝔫𝔦𝔠𝔬𝔡𝔢'); 1 ----------- 7 1 record(s) selected. db2 => VALUES LENGTH('J̲o̲s̲é̲', CODEUNITS16); 1 ----------- 8 1 record(s) selected. db2 => VALUES LENGTH('J̲o̲s̲é̲', CODEUNITS32); 1 ----------- 8 1 record(s) selected. db2 => VALUES CHARACTER_LENGTH('J̲o̲s̲é̲', CODEUNITS32); 1 ----------- 8 1 record(s) selected. db2 => VALUES LENGTH2('J̲o̲s̲é̲'); 1 ----------- 8 1 record(s) selected. db2 => VALUES LENGTH4('J̲o̲s̲é̲'); 1 ----------- 8 1 record(s) selected.
Byte Length
With SQL only:
VALUES LENGTH('møøse');
VALUES LENGTHB('møøse');
VALUES LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢');
VALUES LENGTHB('𝔘𝔫𝔦𝔠𝔬𝔡𝔢');
VALUES LENGTH('J̲o̲s̲é̲');
VALUES LENGTHB('J̲o̲s̲é̲');
Output:
db2 -t db2 => VALUES LENGTH('møøse'); 1 ----------- 7 1 record(s) selected. db2 => VALUES LENGTHB('møøse'); 1 ----------- 7 1 record(s) selected. db2 => VALUES LENGTH('𝔘𝔫𝔦𝔠𝔬𝔡𝔢'); 1 ----------- 28 1 record(s) selected. db2 => VALUES LENGTHB('𝔘𝔫𝔦𝔠𝔬𝔡𝔢'); 1 ----------- 28 1 record(s) selected. db2 => VALUES LENGTH('J̲o̲s̲é̲'); 1 ----------- 13 1 record(s) selected. db2 => VALUES LENGTHB('J̲o̲s̲é̲'); 1 ----------- 13 1 record(s) selected.
Standard ML
Byte Length
val strlen = size "Hello, world!";
Character Length
val strlen = UTF8.size "Hello, world!";
Stata
Use strlen for byte length, and ustrlen for the number of Unicode characters in a string.
scalar s="Ἐν ἀρχῇ ἐποίησεν ὁ θεὸς τὸν οὐρανὸν καὶ τὴν γῆν"
di strlen(s)
97
di ustrlen(s)
47
Stringle
The only current implementation of Stringle uses 8-bit character sets, meaning character and byte length is always the same.
This prints the length of a string from input:
$ #$
Swift
Grapheme Length
Swift has a concept of "character" that goes beyond Unicode code points. A Character
is a "Unicode grapheme cluster", which can consist of one or more Unicode code points.
To count "characters" (Unicode grapheme clusters):
let numberOfCharacters = "møøse".characters.count // 5
let numberOfCharacters = count("møøse") // 5
let numberOfCharacters = countElements("møøse") // 5
Character Length
To count Unicode code points:
let numberOfCodePoints = "møøse".unicodeScalars.count // 5
let numberOfCodePoints = count("møøse".unicodeScalars) // 5
let numberOfCodePoints = countElements("møøse".unicodeScalars) // 5
Byte Length
This depends on which encoding you want to use.
For length in UTF-8, count the number of UTF-8 code units:
let numberOfBytesUTF8 = "møøse".utf8.count // 7
let numberOfBytesUTF8 = count("møøse".utf8) // 7
let numberOfBytesUTF8 = countElements("møøse".utf8) // 7
For length in UTF-16, count the number of UTF-16 code units, and multiply by 2:
let numberOfBytesUTF16 = "møøse".utf16.count * 2 // 10
let numberOfBytesUTF16 = count("møøse".utf16) * 2 // 10
let numberOfBytesUTF16 = countElements("møøse".utf16) * 2 // 10
Symsyn
Byte Length
c : 'abcdefgh'
#c []
Output:
8
TAV
s =: "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
print (quote s), s.Count, s.Bytes
s =: "José&e10;"
print (quote s), s.Count, s.Bytes
s =: "J̲o̲s̲é̲"
print (quote s), s.Count, s.Bytes
- Output:
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢" 7 28 "José⏨" 5 8 "J̲o̲s̲é̲" 9 14
Tcl
Byte Length
Formally, Tcl does not guarantee to use any particular representation for its strings internally (the underlying implementation objects can hold strings in at least three different formats, mutating between them as necessary) so the way to calculate the "byte length" of a string can only be done with respect to some user-selected encoding. This is done this way (for UTF-8):
string length [encoding convertto utf-8 $theString]
Thus, we have these examples:
set s1 "hello, world"
set s2 "\u304A\u306F\u3088\u3046"
set enc utf-8
puts [format "length of \"%s\" in bytes is %d" \
$s1 [string length [encoding convertto $enc $s1]]]
puts [format "length of \"%s\" in bytes is %d" \
$s2 [string length [encoding convertto $enc $s2]]]
Character Length
Basic version:
string length "Hello, world!"
or more elaborately, needs Interpreter any 8.X. Tested on 8.4.12.
fconfigure stdout -encoding utf-8; #So that Unicode string will print correctly
set s1 "hello, world"
set s2 "\u304A\u306F\u3088\u3046"
puts [format "length of \"%s\" in characters is %d" $s1 [string length $s1]]
puts [format "length of \"%s\" in characters is %d" $s2 [string length $s2]]
TI-89 BASIC
The TI-89 uses an fixed 8-bit encoding so there is no difference between character length and byte length.
■ dim("møøse") 5
Toka
Byte Length
" hello, world!" string.getLength
Trith
Character Length
"møøse" length
Byte Length
"møøse" size
TUSCRIPT
Character Length
$$ MODE TUSCRIPT
string="hello, world"
l=LENGTH (string)
PRINT "character length of string '",string,"': ",l
Output:
Character length of string 'hello, world': 12
UNIX Shell
Byte length via external utility:
string='Hello, world!'
length=`expr "x$string" : '.*' - 1`
echo $length # if you want it printed to the terminal
With SUSv3 parameter expansion modifier:
This returns the byte count in ash/dash, but the character count in bash, ksh, and zsh:
string='Hello, world!'
length=${#string}
echo $length # if you want it printed to the terminal
Vala
Character Length
string s = "Hello, world!";
int characterLength = s.length;
VBA
Cf. VBScript (below).
VBScript
Byte Length
LenB(string|varname)
Returns the number of bytes required to store a string in memory. Returns null if string|varname is null.
Character Length
Len(string|varname)
Returns the length of the string|varname . Returns null if string|varname is null.
Visual Basic
same as #VBScript.
Visual Basic .NET
Compiler: Roslyn Visual Basic (language version >=15.5)
Strings in .NET are immutable wrappers around arrays of the Char
type, which represents a UTF-16 code unit (with a size of two bytes). Classes for encoding and decoding strings to and from byte arrays in various encodings are located in the System.Text
namespace, with System.Text.Encoding
representing different string encodings (and providing means of encoding and decoding strings to raw byte arrays). The Length property of a string returns the number of Chars it contains, and is thus the number of UTF-16 code units in that string.
Byte Length
One method of Encoding returns the number of bytes required to encode a .NET string in that encoding (encoding objects can be obtained through readonly static [Shared in VB.NET] properties of the Encoding class).
Module ByteLength
Function GetByteLength(s As String, encoding As Text.Encoding) As Integer
Return encoding.GetByteCount(s)
End Function
End Module
Character Length
There is no intended means of obtaining the number of code points in a string in .NET, though a straightforward implementation is to take one fourth of the string's byte length in UTF-32 (as UTF-32 is a fixed-length encoding where each code point is four bytes).
An alternative implementation is to count the number of UTF-16 surrogate pairs in a string and subtract that number from the number of UTF-16 code units in the string.
Module CharacterLength
Function GetUTF16CodeUnitsLength(s As String) As Integer
Return s.Length
End Function
Private Function GetUTF16SurrogatePairCount(s As String) As Integer
GetUTF16SurrogatePairCount = 0
For i = 1 To s.Length - 1
If Char.IsSurrogatePair(s(i - 1), s(i)) Then GetUTF16SurrogatePairCount += 1
Next
End Function
Function GetCharacterLength_FromUTF16(s As String) As Integer
Return GetUTF16CodeUnitsLength(s) - GetUTF16SurrogatePairCount(s)
End Function
Function GetCharacterLength_FromUTF32(s As String) As Integer
Return GetByteLength(s, Text.Encoding.UTF32) \ 4
End Function
End Module
Grapheme Length
System.Globalization.StringInfo
provides a means of enumerating the text elements of a string, where each "text element" is a Unicode grapheme.
Module GraphemeLength
' Wraps an IEnumerator, allowing it to be used as an IEnumerable.
Private Iterator Function AsEnumerable(enumerator As IEnumerator) As IEnumerable
Do While enumerator.MoveNext()
Yield enumerator.Current
Loop
End Function
Function GraphemeCount(s As String) As Integer
Dim elements = Globalization.StringInfo.GetTextElementEnumerator(s)
Return AsEnumerable(elements).OfType(Of String).Count()
End Function
End Module
Test Code
The compiler constant PRINT_TESTCASE
toggles whether to write the contents of each test case to the console; disable for inputs that may mess with the console.
#Const PRINT_TESTCASE = True
Module Program
ReadOnly TestCases As String() =
{
"Hello, world!",
"møøse",
"𝔘𝔫𝔦𝔠𝔬𝔡𝔢", ' String normalization of the file makes the e and diacritic in é̲ one character, so use VB's char "escapes"
$"J{ChrW(&H332)}o{ChrW(&H332)}s{ChrW(&H332)}e{ChrW(&H301)}{ChrW(&H332)}"
}
Sub Main()
Const INDENT = " "
Console.OutputEncoding = Text.Encoding.Unicode
Dim writeResult = Sub(s As String, result As Integer) Console.WriteLine("{0}{1,-20}{2}", INDENT, s, result)
For i = 0 To TestCases.Length - 1
Dim c = TestCases(i)
Console.Write("Test case " & i)
#If PRINT_TESTCASE Then
Console.WriteLine(": " & c)
#Else
Console.WriteLine()
#End If
writeResult("graphemes", GraphemeCount(c))
writeResult("UTF-16 units", GetUTF16CodeUnitsLength(c))
writeResult("Cd pts from UTF-16", GetCharacterLength_FromUTF16(c))
writeResult("Cd pts from UTF-32", GetCharacterLength_FromUTF32(c))
Console.WriteLine()
writeResult("bytes (UTF-8)", GetByteLength(c, Text.Encoding.UTF8))
writeResult("bytes (UTF-16)", GetByteLength(c, Text.Encoding.Unicode))
writeResult("bytes (UTF-32)", GetByteLength(c, Text.Encoding.UTF32))
Console.WriteLine()
Next
End Sub
End Module
- Output:
graphemes
corresponds to Grapheme Length in the task description, and either Cd pts
value corresponds with Character Length. Byte lengths are given for three Unicode encodings.
Note that the byte length in UTF-16 is always twice the length of a string due to .NET strings using UTF-16.
Test case 0: Hello, world! graphemes 13 UTF-16 units 13 Cd pts from UTF-16 13 Cd pts from UTF-32 13 bytes (UTF-8) 13 bytes (UTF-16) 26 bytes (UTF-32) 52 Test case 1: møøse graphemes 5 UTF-16 units 5 Cd pts from UTF-16 5 Cd pts from UTF-32 5 bytes (UTF-8) 7 bytes (UTF-16) 10 bytes (UTF-32) 20 Test case 2: 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 graphemes 7 UTF-16 units 14 Cd pts from UTF-16 7 Cd pts from UTF-32 7 bytes (UTF-8) 28 bytes (UTF-16) 28 bytes (UTF-32) 28 Test case 3: J̲o̲s̲é̲ graphemes 4 UTF-16 units 9 Cd pts from UTF-16 9 Cd pts from UTF-32 9 bytes (UTF-8) 14 bytes (UTF-16) 18 bytes (UTF-32) 36
+
V (Vlang)
Byte Length
fn main() {
m := "møøse"
u := "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
j := "J̲o̲s̲é̲"
println("$m.len $m ${m.bytes()}")
println("$u.len $u ${u.bytes()}")
println("$j.len $j ${j.bytes()}")
}
Output:
7 møøse [m, 0xc3, 0xb8, 0xc3, 0xb8, s, e] 28 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 [0xf0, 0x9d, 0x94, 0x98, 0xf0, 0x9d, 0x94, 0xab, 0xf0, 0x9d, 0x94, 0xa6, 0xf0, 0x9d, 0x94, 0xa0, 0xf0, 0x9d, 0x94, 0xac, 0xf0, 0x9d, 0x94, 0xa1, 0xf0, 0x9d, 0x94, 0xa2] 13 J̲o̲s̲é̲ [J, 0xcc, 0xb2, o, 0xcc, 0xb2, s, 0xcc, 0xb2, 0xc3, 0xa9, 0xcc, 0xb2]
Character Length
fn main() {
m := "møøse"
u := "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
j := "J̲o̲s̲é̲"
println("$m.runes().len $m ${m.runes()}")
println("$u.runes().len $u ${u.runes()}")
println("$j.runes().len $j ${j.runes()}")
}
Output:
5 møøse [`m`, `ø`, `ø`, `s`, `e`] 7 𝔘𝔫𝔦𝔠𝔬𝔡𝔢 [`𝔘`, `𝔫`, `𝔦`, `𝔠`, `𝔬`, `𝔡`, `𝔢`] 8 J̲o̲s̲é̲ [`J`, `̲`, `o`, `̲`, `s`, `̲`, `é`, `̲`]
Wren
Byte Length
System.print("møøse".bytes.count)
System.print("𝔘𝔫𝔦𝔠𝔬𝔡𝔢".bytes.count)
System.print("J̲o̲s̲é̲".bytes.count)
- Output:
7 28 13
Character Length
System.print("møøse".count)
System.print("𝔘𝔫𝔦𝔠𝔬𝔡𝔢".count)
System.print("J̲o̲s̲é̲".count)
- Output:
5 7 8
Grapheme Length
import "./upc" for Graphemes
System.print(Graphemes.clusterCount("møøse"))
System.print(Graphemes.clusterCount("𝔘𝔫𝔦𝔠𝔬𝔡𝔢"))
System.print(Graphemes.clusterCount("J̲o̲s̲é̲"))
- Output:
5 7 4
x86 Assembly
Byte Length
The following code uses AT&T syntax and was tested using AS (the portable GNU assembler) under Linux.
.data
string: .asciz "Test"
.text
.globl main
main:
pushl %ebp
movl %esp, %ebp
pushl %edi
xorb %al, %al
movl $-1, %ecx
movl $string, %edi
cld
repne scasb
not %ecx
dec %ecx
popl %edi
;; string length is stored in %ecx register
leave
ret
XPL0
include c:\cxpl\stdlib;
IntOut(0, StrLen("Character length = Byte length = String length = "))
Output:
49
XSLT
Character Length
<?xml version="1.0" encoding="UTF-8"?>
...
<xsl:value-of select="string-length('møøse')" /> <!-- 5 -->
xTalk
Char Length
Note: That older Xtalk languages such as HyperCard's HyperTalk did not support non-ASCII characters natively. LiveCode fully supports multi-byte Unicode characters since version 7. See the LiveCode section for more information.
put the length of "Hello World"
or
put the number of characters in "Hello World" -- 'chars' short for characters is also valid
Byte Length
put the number of bytes in "Hello World" -- use byte keyword in LiveCode for multi-byte Unicode
Yorick
Character Length
strlen("Hello, world!")
Z80 Assembly
The majority of Z80-based hardware predates Unicode so only byte length will be demonstrated for now.
Byte Length
Code is called as a subroutine, i.e. CALL getStringLength
.
; input: HL - pointer to the 0th char of a string.
; outputs length to B. HL will point to the last character in the string just before the terminator.
; length is one-indexed and does not include the terminator. A null string will return 0 in B.
; "Terminator" is a label for a constant that can be configured in the source code. My code uses 0.
; Sample Usage:
; ld hl,MyString
; call GetStringLength
GetStringLength:
ld b,0
loop_getStringLength:
ld a,(hl) ;load the next char
cp Terminator ;is it the terminator?
ret z ;if so, exit.
inc hl ;next char
inc b ;increment the byte count
jr loop_getStringLength
zkl
Although zkl handles 8 bit ASCII natively, it also knows UTF-8 up to 6 bytes. In a string, "\uabcd" (hex) and "\U???;" encode 2 and n byte UTF-8 Unicode characters. It does not handle UTF-16 or 4 byte Unicode. It also knows about the bad spots in UTF-8 (such as overlongs).
If your terminal/editor deals with UTF-8 (mine doesn't), you don't need to use the escapes, just put the unicode characters in quotes (ie the editor inserts UTF bytes, which are non zero).
Character Length
"abc".len() //-->3
"\ufeff\u00A2 \u20ac".len() //-->9 "BOM¢ €"
Byte Length
"abc".len() //-->3
"\ufeff\u00A2 \u20ac".len() //-->9
Data(0,Int,"\ufeff\u00A2 \u20ac") //-->Data(9) (bytes)
"J\u0332o\u0332s\u0332e\u0301\u0332".len() //-->14
"\U1D518;\U1D52B;\U1D526;\U1D520;\U1D52C;\U1D521;\U1D522;".len() //-->28
Character Length
UTF-8 characters are counted, modifiers (such as underscore) are counted as separate characters.
"abc".len(8) //-->3
"\ufeff\u00A2 \u20ac".len(8) //-->4 "BOM¢ €"
"\U1000;".len(8) //-->Exception thrown: ValueError(Invalid UTF-8 string)
"\uD800" //-->SyntaxError : Line 2: Bad Unicode constant (\uD800-\uDFFF)
"J\u0332o\u0332s\u0332e\u0301\u0332".len(8) //-->9 "J̲o̲s̲é̲"
"\U1D518;\U1D52B;\U1D526;\U1D520;\U1D52C;\U1D521;\U1D522;".len(8) //-->7 "𝔘𝔫𝔦𝔠𝔬𝔡𝔢"
https://en.wikipedia.org/wiki/Comparison_of_programming_languages_%28string_functions%29#lengthProperty "Wikipedia" (as page type) with input value "https://en.wikipedia.org/wiki/Comparison_of_programming_languages_%28string_functions%29#length" contains invalid characters or is incomplete and therefore can cause unexpected results during a query or annotation process.
Zig
const std = @import("std");
fn printResults(alloc: std.mem.Allocator, string: []const u8) !void {
const cnt_codepts_utf8 = try std.unicode.utf8CountCodepoints(string);
// There is no sane and portable extended ascii, so the best
// we get is counting the bytes and assume regular ascii.
const cnt_bytes_utf8 = string.len;
const stdout_wr = std.io.getStdOut().writer();
try stdout_wr.print("utf8 codepoints = {d}, bytes = {d}\n", .{ cnt_codepts_utf8, cnt_bytes_utf8 });
const utf16str = try std.unicode.utf8ToUtf16LeWithNull(alloc, string);
const cnt_codepts_utf16 = try std.unicode.utf16CountCodepoints(utf16str);
const cnt_2bytes_utf16 = try std.unicode.calcUtf16LeLen(string);
try stdout_wr.print("utf16 codepoints = {d}, bytes = {d}\n", .{ cnt_codepts_utf16, 2 * cnt_2bytes_utf16 });
}
pub fn main() !void {
var arena_instance = std.heap.ArenaAllocator.init(std.heap.page_allocator);
defer arena_instance.deinit();
const arena = arena_instance.allocator();
const string1: []const u8 = "Hello, world!";
try printResults(arena, string1);
const string2: []const u8 = "møøse";
try printResults(arena, string2);
const string3: []const u8 = "𝔘𝔫𝔦𝔠𝔬𝔡𝔢";
try printResults(arena, string3);
// \u{332} is underscore of previous character, which the browser may not
// copy correctly
const string4: []const u8 = "J\u{332}o\u{332}s\u{332}e\u{301}\u{332}";
try printResults(arena, string4);
}
- Output:
utf8 codepoints = 13, bytes = 13 utf16 codepoints = 13, bytes = 26 utf8 codepoints = 5, bytes = 7 utf16 codepoints = 5, bytes = 10 utf8 codepoints = 7, bytes = 28 utf16 codepoints = 7, bytes = 28 utf8 codepoints = 9, bytes = 14 utf16 codepoints = 9, bytes = 18