You wish to implement a callback method for an object created from a library class that you cannot change.What is the preferred way to accomplish this?
A)Extend the library class.
B)Use an inner class in the interface.
C)Create a new class that mimics the library class.
D)Use a helper class that implements the callback method.

Question

Quizplus · Accepted Answer

Since we cannot change the library class, the preferred way is to use a helper class that implements the callback method. This helper class can be instantiated by the client code and passed as an argument to the library class's method that requires the callback. This way, the client code still has control over the callback method without having to modify the library class or create new classes that mimic it.

You Wish to Implement a Callback Method for an Object