#include <iostream>
#include <string>

using namespace std;


int main() {
    string greeting{"Hello World!"};

    int i;

    cout << greeting  << " is " << greeting.size() << " characters long." 
         << endl;

    i = 0;
    cout << "The string one character at a time " << endl;

    while (i < greeting.size()) {
       cout << greeting[i] << ", ";
       ++i;
    }
    cout << endl << endl;

    cout << "In reverse " << endl;

    i = greeting.length() -1;

    while (i >= 0) {
       cout << greeting[i] << ", ";
       --i;
    }

    cout << endl << endl;

    // make uppper case
    i = 0;
    while (i < greeting.size()) {
       greeting[i] = toupper(greeting[i]); 
       ++i;
    }
    cout << greeting << endl;

    greeting = tolower(greeting);


    return 0;
}