PCPP-32-101 1.6 Understand and Use Abstract Classes and Methods PCPP-32-1 Practice Questions (Page 4)

Questions 16–17

1. 16application · medium

   A developer has an abstract class `Animal` with an abstract method `make_sound()`. They create a subclass `Dog` that implements `make_sound()`. However, they also want to add a new abstract method `move()` to `Animal`. What will happen to `Dog`?

   • A`Dog` will become abstract and cannot be instantiated until `move()` is implemented.
   • B`Dog` will remain concrete because it already implements `make_sound()`.
   • C`Dog` will raise an error at class definition time.
   • D`Dog` will automatically inherit a default implementation of `move()`.
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2. 17application · medium

   A developer is designing a system with an abstract base class `NotificationSender` that has an abstract method `send()`. They want to create multiple concrete senders (e.g., `EmailSender`, `SmsSender`, `PushSender`). What is the main advantage of using an abstract base class here?

   • AIt automatically handles network errors for all senders.
   • BIt allows the developer to instantiate `NotificationSender` and use it as a default sender.
   • CIt ensures that all senders have a `send()` method, enabling polymorphic use.
   • DIt reduces the number of files needed for the project.
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