sizeof(string) does not give you the string's length.

string_size.cpp

#include <iostream>
#include <string>

using std::cout;
using std::endl;
using std::string;

int main()
{
  string sizeStr = "This is a test string that is rather long. Many bytes. Oh yes, quite a few bytes.";
  cout << "The length of sizeStr is " << sizeStr.size() << endl; // The length of sizeStr is 81
  cout << "sizeof(sizeStr) returns " << sizeof(sizeStr) << endl; // sizeof(sizeStr) returns 4
  return 0;
}