Object-oriented programming · interview question
Consider a Product class with a price field. Which approach ensures the price is always positive?
Multiple choiceMediumchapter-3-curatedpremiumoopinvariants-and-validation
Answer and explanation
Correct answer
B. Validate the price in the constructor
Why
Validating the price in the constructor ensures that the object is never created in an invalid state. This approach leverages encapsulation to enforce class invariants, which are rules that must always be true for a correctly functioning object.
Test yourself on Object-oriented programming
A free test with instant, explained results. No account needed.
More Object-oriented programming questions
- In a typical e-commerce application, how should a CartItem object access the price of a Product?
- What design principle is violated if a Cart class directly manipulates a Product's price?
- Why might CartItem hold a Product reference instead of copying every product field into loose variables?
- In the context of e-commerce, which class is most likely to contain a method called calculateTotalPrice()?
- What access modifier should be used for fields to adhere to encapsulation principles?
- How would you explain a key reason to use encapsulation when designing an object with multiple responsibilities in an…