Hey, welcome to day 42 of the course.
You're doing great.
Today, we're going to learn something very important, which I haven't seen in other online courses,
and that is extending your programs because an app, a program is like a living thing.
It grows with time.
In other words, you build a program, but then new ideas come, new requests from users.
So then you might want to add more features to the program.
And when that program is built in P style, that is a good thing because it's very easy to add more
features to that program, to extend that program.
So today what we're going to do is we're going to add a credit card feature to our hotel reservation
program.
So currently our program allows the user to book a hotel.
Using the book method, and then the user gets a reservation ticket generated in the command line.
So there is no payment layer in this app.
Therefore, to satisfy our users and our clients requests, we want to make this program able to check
a credit card.
In other words, we want to validate a credit card in our program that will be a fake credit card.
But the idea is the same.
So with that in mind, I'll see you in the next video.
Let's begin.