convert string to uppercase in cpp code example

Example 1: c++ convert lowercase to uppercase

/* toupper example */
#include <stdio.h>
#include <ctype.h>
int main ()
{
  int i=0;
  char str[]="Test String.\n";
  char c;
  while (str[i])
  {
    c=str[i];
    putchar (toupper(c));
    i++;
  }
  return 0;
}

Example 2: string to upper c++

std::string data = "This is a sample string.";
// convert string to upper case
std::for_each(data.begin(), data.end(), [](char & c){
c = ::toupper(c);
});