String Byte Length

From Rosetta Code
This task has has been split off from another task. Its programming examples are in need of review to ensure that they fit the requirements of the new task.
String Byte Length
You are encouraged to solve this task according to the task description, using any language you may know.

In this task, the goal is to find the byte length of a string. This means encodings like UTF-8 may need to be handled specially, as there is not necessarily a one-to-one relationship between bytes and characters, and some languages recognize this.

For character length, see String Character Length.


$length:=Length("Hello, world!")




Compiler: GCC 4.1.2

Str    : String := "Hello World";
Length : constant Natural := Str'Length;


count of "Hello World"


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, world!" | awk '{print length($0)}'

From executable script: (prints for every line arriving on stdin)

#!/usr/bin/awk -f
{print"The length of this line is "length($0)}


Standard: ANSI C (AKA C89):

Compiler: GCC 3.3.3

 #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;
   char *p = (char *) string;
   while (*p++ != '\0') length++;                                         
   return 0;

or (for arrays of char only)

 #include <stdlib.h>
 int main(void)
   char const s[] = "Hello, world!";
   size_t length = sizeof s - 1;
   return 0;


Standard: ISO C++ (AKA C++98):

Compiler: g++ 4.0.2

 #include <string> // note: not <string.h>
 int main()
   std::string s = "Hello, world!";
   std::string::size_type length = s.length(); // option 1: In Characters/Bytes
   std::string::size_type size = s.size();     // option 2: In Characters/Bytes
   // In bytes same as above since sizeof(char) == 1
   std::string::size_type bytes = s.length() * sizeof(std::string::value_type); 

For wide character strings:

 #include <string>
 int main()
   std::wstring s = L"\u304A\u306F\u3088\u3046";
   std::wstring::size_type length = s.length() * sizeof(std::wstring::value_type); // in bytes


Platform: .NET Language Version: 1.0+

string s = "Hello, world!";
int clength = s.Length;  // In characters
int blength = System.Text.Encoding.GetBytes(s).length; // In Bytes.


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!"


  #len("Hello World")#

Common Lisp

  (length "Hello World")

Component Pascal

  LEN("Hello, World!")


Interpreter: ANS Forth

 CREATE s ," Hello world" \ create string "s"
 s C@ ( -- length )


Interpreter: GHCi 6.6, Hugs

Compiler: GHC 6.6

strlen = length "Hello, world!"


Compiler: any IDL compiler should do

 length = strlen("Hello, world!")


Java encodes strings in UTF-16, which represents each character with one or two 16-bit values. The length method of String 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.

String s = "Hello, world!";
int byteCount = s.length() * 2;

An other way to know the byte length of a string is to explicitly specify the charset we desire.

String s = "Hello, world!";
int byteCountUTF16 = s.getByte("UTF-16").length;
int byteCountUTF8  = s.getByte("UTF-8").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


 //Store length of hello world in length and print it
 . length = "Hello World".length();


Interpreter: Lua 5.0 or later.

 string="Hello world"

mIRC Scripting Language

Interpreter: mIRC

alias stringlength { echo -a Your Name is: $len($$?="Whats your name") letters long! }


Interpreter/Compiler: Ocaml 3.09

String.length "Hello world";;


Interpreter: perl 5.8

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.


 $length = strlen('Hello, world!');


  string VARCHAR2( 50 ) := 'Hello, world!';
  stringlength NUMBER;
  stringlength := length( string );


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);


Interpreter: Python 2.4

length = len("The length of this string will be determined")


 string="Hello world"
 print string.length


 puts "Hello World".length


 (string-length "Hello world")


 string := 'Hello, world!".
 string size.

Standard ML

Interpreter: SML/NJ 110.60, Moscow ML 2.01 (January 2004)

Compiler: MLton 20061107

val strlen = size "Hello, world!";


Basic version:

 string bytelength "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 bytes is %d"  $s1 [string bytelength $s1]]
 puts [format "length of \"%s\" in bytes is %d"  $s2 [string bytelength $s2]]


This will include the terminating 0 in the length.

 " hello, world!" count 

UNIX Shell

With external utilities:

Interpreter: any bourne shell

 string='Hello, world!'
 length=`echo -n "$string" | wc -c | tr -dc '0-9'`
 echo $length # if you want it printed to the terminal

With SUSv3 parameter expansion modifier:

Interpreter: Almquist SHell (NetBSD 3.0), Bourne Again SHell 3.2, Korn SHell (5.2.14 99/07/13.2), Z SHell

 string='Hello, world!'
 echo $length # if you want it printed to the terminal



Returns the number of bytes required to store a string in memory Returns null if string|varname is null


Interpreter: HyperCard

 put the length of "Hello World"


 put the number of characters in "Hello World"