convert whole string to uppercase c 2b 2b

1#include<bits/stdc++.h> 
2using namespace std; 
3  
4int main() 
5{ 
6    string s = "Viet Nam"; 
7    transform(s.begin(), s.end(), s.begin(), ::toupper);  //uppercase
8    cout << s << endl; 
9    return 0; 
10}
11

1/* toupper example */
2#include <stdio.h>
3#include <ctype.h>
4int main ()
5{
6  int i=0;
7  char str[]="Test String.\n";
8  char c;
9  while (str[i])
10  {
11    c=str[i];
12    putchar (toupper(c));
13    i++;
14  }
15  return 0;
16}

1std::string data = "This is a sample string.";
2// convert string to upper case
3std::for_each(data.begin(), data.end(), [](char & c){
4c = ::toupper(c);
5});

1int i = 0;
2    while(str[i])
3    {
4        if(str[i] == std::toupper(str[i]) && std::isalpha(str[i]) == 1024)
5        str[i]+= 32;
6        ++i;
7    }