c++ convert lowercase to uppercase

// Include #include<bits/stdc++.h>
string s = "Jatin Goyal"; 
// using transform() function and ::tolower in STL 
transform(s.begin(), s.end(), s.begin(), ::tolower); 

/* 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;
}