IB Computer Science Topic B3.2: Fundamentals of OOP for Multiple Classes Questionbank

(c) Discuss whether modelling the liner as a separate class is worthwhile, given that it holds only a material name.

A camera museum's Camera class provides a method catalogue_entry that all cameras inherit. The FilmCamera class overrides it, and the DigitalCamera class does not. Explain what happens when catalogue_entry is called on a DigitalCamera object.

A monitoring company uses the factory design pattern to create Sensor objects from records read from a file, where each record names the kind of sensor. Explain how this pattern helps.

TransportFleet Inc. has a Vehicle class with a startEngine() method that performs basic engine startup. Their Car and Motorcycle subclasses need different starting procedures: cars require fuel pump priming and automatic transmission checks, while motorcycles need kickstand safety checks.

(a) Define what is meant by "method overriding" in object-oriented programming.

(b) Describe the rules and requirements for properly overriding methods in inheritance hierarchies.

(c) Using the TransportFleet case study, explain how method overriding would be implemented for the different starting procedures and what precautions should be taken.

A livestock system's Animal class provides a method daily_feed returning a quantity in kilograms, calculated as one thirtieth of the animal's mass. The Cow class must return one and a half times that amount. Construct the Cow class so that it inherits from Animal and overrides daily_feed, reusing the calculation defined in Animal rather than repeating it.