but every instance of a bank account has a different number. The account ID is constant on a per-account basis, but it's not the same for every account. That's how final variables work. What is a ...

This is because Java is “statically-typed” as opposed ... depending on how they interact with their class (instance variables vs static variables). You won’t need to understand these ...

Abstract classes and interfaces in Java serve ... manipulates instance variables within concrete methods. From an object-oriented programming perspective, the main difference between an interface ...