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std::strlen(3)		      C++ Standard Libary		std::strlen(3)

NAME
       std::strlen - std::strlen

Synopsis
	  Defined in header <cstring>
	  std::size_t strlen( const char* str );

	  Returns  the length of the given byte	string,	that is, the number of
       characters in a
	  character array whose	first element is pointed to by str up  to  and
       not including the
	  first	 null character. The behavior is undefined if there is no null
       character in the
	  character array pointed to by	str.

Parameters
	  str -	pointer	to the null-terminated byte string to be examined

Return value
	  The length of	the null-terminated string str.

Possible implementation
	  std::size_t strlen(const char* start)	{
	     //	NB: no nullptr checking!
	     const char* end = start;
	     for( ; *end != '\0'; ++end)
		;
	     return end	- start;
	  }

Example
       // Run this code

	#include <cstring>
	#include <iostream>

	int main()
	{
	   const char str[] = "How many	characters does	this string contain?";

	   std::cout <<	"without null character: " << std::strlen(str) << '\n'
		     <<	"with null character: "	<< sizeof str << '\n';
	}

Output:
	without	null character:	45
	with null character: 46

See also
	  wcslen returns the length of a wide string
		 (function)
	  mblen	 returns the number of bytes in	the next multibyte character
		 (function)

http://cppreference.com		  2022.07.31			std::strlen(3)

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