The goal of these modules is to introduce myself to Object-Oriented Programming.
Ex00: upon ./megaphone call, converts argument into UPPERCASE, otherwise displays no argument message.
Ex01: Its a phonebook, called by ./phonebook, it accepts 3 commands which prompt the user into loading the contacts table.
Ex02: A superb accounting system had its source code lost, but with its class and tests file the code could be remade so that by calling ./main it will display the same output as before.