Behavioral Design Patterns Quiz (v3)

Q1. What is the primary focus of behavioral design patterns? Creating objects and instances
How classes and objects interact and distribute responsibility
Simplifying the structure of complex class hierarchies
Optimizing database transactions

Q2. Which behavioral design pattern allows objects to notify other objects about changes in their state? Strategy Pattern
Observer Pattern
Mediator Pattern
Memento Pattern

Q3. In the Chain of Responsibility pattern, what happens when a request is received? It is simultaneously processed by all handlers
It is processed by a central dispatcher
It is passed along a chain of handlers until one handles it
It is transformed into a different request type

Q4. The Template Method pattern establishes: A flexible way to compose objects
A skeleton of an algorithm with some steps deferred to subclasses
A way to create objects without specifying their concrete classes
A unified interface to a set of interfaces in a subsystem

Q5. Which behavioral pattern would be most appropriate for implementing an undo functionality in a text editor? Command Pattern
Iterator Pattern
Memento Pattern
Visitor Pattern

Q6. How does the Observer pattern differ from the Mediator pattern? Observer allows one-to-many dependencies while Mediator handles many-to-many
Observer works with collections while Mediator works with individual objects
Observer is a behavioral pattern while Mediator is a structural pattern
Observer requires concrete classes while Mediator uses only interfaces

Q7. In which scenario would the State pattern be most appropriate? When an algorithm needs to vary independently from the clients that use it
When an object needs to change its behavior based on its internal state
When a complex object needs to be built step by step
When operations need to be added to an object without modifying it

Q8. Which combination of patterns would best address a system where multiple UI components need to respond to events, maintain a history of states, and support undo operations? Factory, Singleton, and Decorator
Observer, Command, and Memento
Template Method, Bridge, and Proxy
Chain of Responsibility, Strategy, and Adapter

Q9. Consider a complex validation system that performs sequential checks on data with the ability to stop at any point if validation fails. Which pattern implementation would be most effective if new validation rules need to be frequently added or removed without modifying existing code? A Visitor pattern with composite validators
A Chain of Responsibility with dynamic handler registration
A Strategy pattern with conditional execution
A Template Method with hook methods for each validation step

Q10. What potential issue might arise when implementing the Observer pattern in a multi-threaded environment? Memory leaks due to circular references
Race conditions during notification of multiple observers
Increased coupling between the subject and observers
All of the above

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