Why should calculation methods be in classes like CartItem?
How does method design impact object interaction?
How do instance methods interact with object fields?
Why place behavior on the object it acts upon?
Why does constructors in Java matter in this design?
What's a key advantage of using getters and setters?
What are the implications of not using instance methods?
Why check stock in the Product class?
How can method placement affect object interaction?
When does behavior belong on the object itself?