String length, in C++

C++

auto utf8len(std::string_view const& s) -> size_t
{
	std::setlocale(LC_ALL, "en_US.utf8");

	auto n = size_t{};
	auto size = size_t{};
	auto mb = std::mbstate_t{};

	while(size < s.length())
	{
		size += mbrlen(s.data() + size, s.length() - size, &mb);
		n += 1;
	}

	return n;
}

Ada

n : Integer := s'Length;

Clojure

(defn n[s] (.codePointCount s 0 (count s)))

Clojure

(def n (.codePointCount s 0 (count s)))

Cobol

IDENTIFICATION DIVISION.
PROGRAM-ID. length.
PROCEDURE DIVISION.
   MOVE FUNCTION LENGTH(s) TO n
STOP RUN.

C#

int n = s.Length;

D

size_t n = s.walkLength;

D

size_t n = s.length;

D

size_t n = s.byGrapheme.walkLength;

Dart

int n = s.length;

Elixir

n = String.length s

Erlang

N = string:length(S)

Fortran

n = len(s)

Go

n := utf8.RuneCountInString(s)

Haskell

n = length s

JS

const n = s.length;

JS

const n = [...s].length;

Java

int n = s.length();

Kotlin

val n = s.length

Lisp

(setf n (length s))

Lisp

(length s)

Lua

local utf8={}
function utf8.bytes(str,index)
 local byte=string.byte(str,index)
 local ret
 if     byte==nil then ret=0
 elseif byte<128  then ret=1
 elseif byte<192  then ret=2
 elseif byte<224  then ret=3
 else                  ret=4
 end
 return ret
end
function utf8.len(str)
 local count=0
 local fini=#str+1
 local index=1
 while index~=fini do
  count=count+1
  index=index+utf8.bytes(str,index)
 end
 return count
end
local n=utf8.len(s)