the make system login, the login system for receiving user input to the process of signing up, then store in an array of user login, to be able to determine any array length, then use to process validation, according to whether the user is already signed up.
1. using the concept of java (object-based programs)
2. using an array of objects
3. menggunakanscanner to accept user input
4. able to improvise by using the console to accept input class password (a plus).