to upper in cpp code example

Example 1: convert whole string to uppercase c++

#include<bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    string s = "Viet Nam"; 
    transform(s.begin(), s.end(), s.begin(), ::toupper);  //uppercase
    cout << s << endl; 
    return 0; 
}

Example 2: toupper c++

int result = toupper(charecterVariable);// return the int that corresponding upper case char
//if there is none then it will return the int for the original input.
//can convert int to char after
char result2 = (char)toupper(variableChar);