Can a java program have only one class ??

Question

As I saw this image :-

https://www.dropbox.com/s/rsz10uvyymtt4n0/IMG_20170625_105601.jpg?dl=0

Please tell if we can have more than one class

Answer 1

Oh certainly not! The best way to plan out a Java program is to think in terms of how multiple objects will interact in order to do the work you need done!

That's not too say you can't cram a whole program into a single class, but that defeats the purpose of OOP. I wouldn't recommend it.