How does the Command Pattern support the implementation of an 'undo' functionality?
By preventing any actions from being executed in the first place.
By relying on the operating system's built-in undo functionality.
By directly modifying the state of the application to revert changes.
By providing a mechanism to reverse the actions performed by a command.
In a scenario where you are designing a game with different enemy types, how might the Factory Method pattern be applied?
Create a single factory class responsible for instantiating all enemy types based on given parameters.
Define an abstract 'EnemyFactory' with a 'createEnemy' method, and have subclasses for each enemy type implement their creation logic.
Use a dependency injection framework to inject concrete enemy instances into the game logic.
Hardcode the instantiation of each enemy type directly within the game logic where needed.
When might the Strategy Pattern introduce unnecessary complexity?
When you have a small number of algorithms that are unlikely to change.
When the context needs to be aware of the concrete strategy being used.
When the algorithms are very similar and could be easily combined into a single class.
When performance is absolutely critical, and the overhead of strategy objects is a concern.
What is the primary intent of the Factory Method pattern in software development?
To reduce code duplication by reusing object creation code across classes.
To enforce strict object creation rules through a central factory class.
To delegate object creation to subclasses, promoting extensibility.
To create objects directly within a class, exposing instantiation logic.
What potential issue could arise if an observer modifies the subject's state during notification?
It could lead to an infinite loop.
It could result in unexpected behavior and make the system harder to reason about.
All of the above
It violates the principle of least astonishment.
Which of these scenarios would be a suitable use case for the Decorator Pattern?
Representing a family tree with complex relationships between members.
Managing the state of an object throughout its lifecycle.
Implementing a logging system that can be added to different parts of an application.
Creating different types of vehicles with varying features.
Which of the following is a potential drawback of the Singleton pattern?
It makes unit testing more challenging.
It simplifies dependency injection.
It promotes code reusability.
It reduces the need for global variables.
What is a key consideration when implementing the Singleton pattern in a multi-threaded application?
Avoiding any form of synchronization to improve performance.
Ensuring that only one instance can be created, even under concurrent access.
Creating separate instances for each thread.
Using global variables to store the Singleton instance.
Design patterns primarily target which aspect of software development?
Code compilation speed
Application security
Database optimization
Code structure and organization
Which of the following real-world analogies best describes the Adapter Pattern?
A restaurant menu listing available dishes and their prices.
A car factory producing different models of cars.
A coffee machine using different types of coffee capsules.
A universal travel adapter allowing different plugs to fit into a socket.