std::strlen

 

C++

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Null-terminated byte strings

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

Returns the length of the given null-terminated byte string, that is, the number of characters that precede the terminating null character.

Parameters

str

-

pointer to the null-terminated byte string to be examined

Return value

The length of the null-terminated string str.

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

C documentation for strlen