Question

I want to write a Person class that has their details, including a username and password.

What I want then to do is create a login where the user types in their username and password and then it gets checked for every instance that has been created of that class

if (p1.getUser == userInput && p1.getPass == passInput)
{
    Login();
}
else
.... Check the next instance until you've checked every instance.

Can anyone think of a good way to pull that off?

Answer 1

I would (basically like every web site on the planet) store the users in a database and use a query to find them:

select * from my_user where username = ? and password = ?

Note: Normally, the password is saved as the hash rather than the plain text

However, if you really want a code-only solution, do this:

List<Person> people = new ArrayList<Person>();
// populate people

public Person login(String username, String password) {
    for (Person person : people) {
       if (person.getUser().equalsIgnoreCase(username) &&
           person.getPass().equals(password))
           return person;
    }
    return null;
}