Convert String to uppercase

convertStrCase.cpp

#include <iostream>
#include <string>
#include <stdio.h>
#include <ctype.h>

using namespace std;

int main(){
    string s="small";
    int i=0;
    char c2;
    while(s[i]){
        c2=s[i];
        if(islower(c2)){
            c2=toupper(c2);
        };
        cout<<c2;
        i++;
    };
    return 0;
}