Java Design Patterns MCQ Questions with Answers (Latest 2026)

Q1. Which option best describes Singleton in Java?

A. A pattern that destroys objects. B. Single instance with global access; thread-safety needed. C. A factory creating new instances always. D. A pure observer.

Select an answer to check.

Answer: Single instance with global access; thread-safety needed.

Here, Single instance with global access; thread-safety needed. is the right choice. Use enum or holder idiom in Java. It aligns directly with what the question asks about which option best describes singleton in java. A quick elimination of partially true options helps confirm it.

Q2. What is the primary purpose of Singleton?

A. A pattern that destroys objects. B. A factory creating new instances always. C. Single instance with global access; thread-safety needed. D. A pure observer.

Select an answer to check.

Answer: Single instance with global access; thread-safety needed.

In this case, Single instance with global access; thread-safety needed. is correct. Use enum or holder idiom in Java. It aligns directly with what the question asks about what is the primary purpose of singleton. A quick elimination of partially true options helps confirm it.

Q3. Which statement about Singleton is most accurate?

A. A pattern that destroys objects. B. A factory creating new instances always. C. Single instance with global access; thread-safety needed. D. A pure observer.

Select an answer to check.

Answer: Single instance with global access; thread-safety needed.

The best option here is Single instance with global access; thread-safety needed.. Use enum or holder idiom in Java. It aligns directly with what the question asks about which statement about singleton is most accurate. A quick elimination of partially true options helps confirm it.

Q4. How is Singleton best characterized?

A. Single instance with global access; thread-safety needed. B. A factory creating new instances always. C. A pure observer. D. A pattern that destroys objects.

Select an answer to check.

Answer: Single instance with global access; thread-safety needed.

For this question, Single instance with global access; thread-safety needed. is correct. Use enum or holder idiom in Java. It aligns directly with what the question asks about how is singleton best characterized. A quick elimination of partially true options helps confirm it.

Q5. Which option best describes Factory Method in Java?

A. A pure singleton. B. Defines an interface for creating an object. C. An adapter. D. A pattern with no creation logic.

Select an answer to check.

Answer: Defines an interface for creating an object.

Defines an interface for creating an object. is the correct answer here. Subclasses decide which class. It aligns directly with what the question asks about which option best describes factory method in java. A quick elimination of partially true options helps confirm it.

Q6. What is the primary purpose of Factory Method?

A. A pure singleton. B. Defines an interface for creating an object. C. A pattern with no creation logic. D. An adapter.

Select an answer to check.

Answer: Defines an interface for creating an object.

Here, Defines an interface for creating an object. is the right choice. Subclasses decide which class. This matches the core idea being tested around what is the primary purpose of factory method. A quick elimination of partially true options helps confirm it.

Q7. Which statement about Factory Method is most accurate?

A. Defines an interface for creating an object. B. A pattern with no creation logic. C. A pure singleton. D. An adapter.

Select an answer to check.

Answer: Defines an interface for creating an object.

In this case, Defines an interface for creating an object. is correct. Subclasses decide which class. This matches the core idea being tested around which statement about factory method is most accurate. A quick elimination of partially true options helps confirm it.

Q8. How is Factory Method best characterized?

A. A pure singleton. B. Defines an interface for creating an object. C. An adapter. D. A pattern with no creation logic.

Select an answer to check.

Answer: Defines an interface for creating an object.

The best option here is Defines an interface for creating an object.. Subclasses decide which class. This matches the core idea being tested around how is factory method best characterized. A quick elimination of partially true options helps confirm it.

Q9. Which option best describes Abstract Factory in Java?

A. Family of related factories. B. A pure builder. C. A prototype. D. Single factory only.

Select an answer to check.

Answer: Family of related factories.

For this question, Family of related factories. is correct. Theme/family swaps. This matches the core idea being tested around which option best describes abstract factory in java. A quick elimination of partially true options helps confirm it.

Q10. What is the primary purpose of Abstract Factory?

A. A pure builder. B. Family of related factories. C. Single factory only. D. A prototype.

Select an answer to check.

Answer: Family of related factories.

Family of related factories. is the correct answer here. Theme/family swaps. This matches the core idea being tested around what is the primary purpose of abstract factory. A quick elimination of partially true options helps confirm it.

Q11. Which statement about Abstract Factory is most accurate?

A. Single factory only. B. Family of related factories. C. A pure builder. D. A prototype.

Select an answer to check.

Answer: Family of related factories.

Here, Family of related factories. is the right choice. Theme/family swaps. That is exactly the concept behind which statement about abstract factory is most accurate in this context. A quick elimination of partially true options helps confirm it.

Q12. How is Abstract Factory best characterized?

A. Single factory only. B. A prototype. C. Family of related factories. D. A pure builder.

Select an answer to check.

Answer: Family of related factories.

In this case, Family of related factories. is correct. Theme/family swaps. That is exactly the concept behind how is abstract factory best characterized in this context. A quick elimination of partially true options helps confirm it.

Q13. Which option best describes Builder in Java?

A. Step-by-step construction; immutable end product. B. A factory method. C. Direct constructor calls. D. A pure singleton.

Select an answer to check.

Answer: Step-by-step construction; immutable end product.

The best option here is Step-by-step construction; immutable end product.. Common in Java for many params. That is exactly the concept behind which option best describes builder in java in this context. A quick elimination of partially true options helps confirm it.

Q14. What is the primary purpose of Builder?

A. A factory method. B. Direct constructor calls. C. A pure singleton. D. Step-by-step construction; immutable end product.

Select an answer to check.

Answer: Step-by-step construction; immutable end product.

For this question, Step-by-step construction; immutable end product. is correct. Common in Java for many params. That is exactly the concept behind what is the primary purpose of builder in this context. A quick elimination of partially true options helps confirm it.

Q15. Which statement about Builder is most accurate?

A. Direct constructor calls. B. Step-by-step construction; immutable end product. C. A factory method. D. A pure singleton.

Select an answer to check.

Answer: Step-by-step construction; immutable end product.

Step-by-step construction; immutable end product. is the correct answer here. Common in Java for many params. That is exactly the concept behind which statement about builder is most accurate in this context. A quick elimination of partially true options helps confirm it.

Q16. How is Builder best characterized?

A. A factory method. B. A pure singleton. C. Step-by-step construction; immutable end product. D. Direct constructor calls.

Select an answer to check.

Answer: Step-by-step construction; immutable end product.

Here, Step-by-step construction; immutable end product. is the right choice. Common in Java for many params. It fits the requirement in the prompt about how is builder best characterized. A quick elimination of partially true options helps confirm it.

Q17. Which option best describes Prototype in Java?

A. Always new() construction. B. A factory by reflection only. C. A pure singleton. D. Clone existing instances.

Select an answer to check.

Answer: Clone existing instances.

In this case, Clone existing instances. is correct. Cheap construction by copy. It fits the requirement in the prompt about which option best describes prototype in java. A quick elimination of partially true options helps confirm it.

Q18. What is the primary purpose of Prototype?

A. A pure singleton. B. A factory by reflection only. C. Always new() construction. D. Clone existing instances.

Select an answer to check.

Answer: Clone existing instances.

The best option here is Clone existing instances.. Cheap construction by copy. It fits the requirement in the prompt about what is the primary purpose of prototype. A quick elimination of partially true options helps confirm it.

Q19. Which statement about Prototype is most accurate?

A. Always new() construction. B. A pure singleton. C. A factory by reflection only. D. Clone existing instances.

Select an answer to check.

Answer: Clone existing instances.

For this question, Clone existing instances. is correct. Cheap construction by copy. It fits the requirement in the prompt about which statement about prototype is most accurate. A quick elimination of partially true options helps confirm it.

Q20. How is Prototype best characterized?

A. Always new() construction. B. A factory by reflection only. C. Clone existing instances. D. A pure singleton.

Select an answer to check.

Answer: Clone existing instances.

Clone existing instances. is the correct answer here. Cheap construction by copy. It fits the requirement in the prompt about how is prototype best characterized. A quick elimination of partially true options helps confirm it.

Q21. Which option best describes Adapter in Java?

A. A composite. B. A facade. C. A decorator. D. Bridges two incompatible interfaces.

Select an answer to check.

Answer: Bridges two incompatible interfaces.

Here, Bridges two incompatible interfaces. is the right choice. Wraps to convert API. This is the most accurate statement for which option best describes adapter in java. A quick elimination of partially true options helps confirm it.

Q22. What is the primary purpose of Adapter?

A. Bridges two incompatible interfaces. B. A decorator. C. A composite. D. A facade.

Select an answer to check.

Answer: Bridges two incompatible interfaces.

In this case, Bridges two incompatible interfaces. is correct. Wraps to convert API. This is the most accurate statement for what is the primary purpose of adapter. A quick elimination of partially true options helps confirm it.

Q23. Which statement about Adapter is most accurate?

A. A decorator. B. Bridges two incompatible interfaces. C. A facade. D. A composite.

Select an answer to check.

Answer: Bridges two incompatible interfaces.

The best option here is Bridges two incompatible interfaces.. Wraps to convert API. This is the most accurate statement for which statement about adapter is most accurate. A quick elimination of partially true options helps confirm it.

Q24. How is Adapter best characterized?

A. A composite. B. A decorator. C. A facade. D. Bridges two incompatible interfaces.

Select an answer to check.

Answer: Bridges two incompatible interfaces.

For this question, Bridges two incompatible interfaces. is correct. Wraps to convert API. This is the most accurate statement for how is adapter best characterized. A quick elimination of partially true options helps confirm it.

Q25. Which option best describes Bridge in Java?

A. Decouples abstraction from implementation. B. Decorator pattern. C. Composite pattern. D. Adapter pattern.

Select an answer to check.

Answer: Decouples abstraction from implementation.

Decouples abstraction from implementation. is the correct answer here. Vary independently. This is the most accurate statement for which option best describes bridge in java. A quick elimination of partially true options helps confirm it.

Q26. What is the primary purpose of Bridge?

A. Composite pattern. B. Adapter pattern. C. Decouples abstraction from implementation. D. Decorator pattern.

Select an answer to check.

Answer: Decouples abstraction from implementation.

Here, Decouples abstraction from implementation. is the right choice. Vary independently. It aligns directly with what the question asks about what is the primary purpose of bridge. The other options are either incomplete or contextually incorrect.

Q27. Which statement about Bridge is most accurate?

A. Decorator pattern. B. Decouples abstraction from implementation. C. Composite pattern. D. Adapter pattern.

Select an answer to check.

Answer: Decouples abstraction from implementation.

In this case, Decouples abstraction from implementation. is correct. Vary independently. It aligns directly with what the question asks about which statement about bridge is most accurate. The other options are either incomplete or contextually incorrect.

Q28. How is Bridge best characterized?

A. Composite pattern. B. Adapter pattern. C. Decouples abstraction from implementation. D. Decorator pattern.

Select an answer to check.

Answer: Decouples abstraction from implementation.

The best option here is Decouples abstraction from implementation.. Vary independently. It aligns directly with what the question asks about how is bridge best characterized. The other options are either incomplete or contextually incorrect.

Q29. Which option best describes Composite in Java?

A. A pure singleton. B. A pure decorator. C. Treat objects and groups uniformly. D. A pure adapter.

Select an answer to check.

Answer: Treat objects and groups uniformly.

For this question, Treat objects and groups uniformly. is correct. Tree structures. It aligns directly with what the question asks about which option best describes composite in java. The other options are either incomplete or contextually incorrect.

Q30. What is the primary purpose of Composite?

A. A pure adapter. B. Treat objects and groups uniformly. C. A pure decorator. D. A pure singleton.

Select an answer to check.

Answer: Treat objects and groups uniformly.

Treat objects and groups uniformly. is the correct answer here. Tree structures. It aligns directly with what the question asks about what is the primary purpose of composite. The other options are either incomplete or contextually incorrect.

Q31. Which statement about Composite is most accurate?

A. A pure adapter. B. A pure singleton. C. A pure decorator. D. Treat objects and groups uniformly.

Select an answer to check.

Answer: Treat objects and groups uniformly.

Here, Treat objects and groups uniformly. is the right choice. Tree structures. This matches the core idea being tested around which statement about composite is most accurate. The other options are either incomplete or contextually incorrect.

Q32. How is Composite best characterized?

A. A pure adapter. B. A pure singleton. C. A pure decorator. D. Treat objects and groups uniformly.

Select an answer to check.

Answer: Treat objects and groups uniformly.

In this case, Treat objects and groups uniformly. is correct. Tree structures. This matches the core idea being tested around how is composite best characterized. The other options are either incomplete or contextually incorrect.

Q33. Which option best describes Decorator in Java?

A. Wraps to add behavior. B. Replaces inheritance entirely. C. Adapter pattern. D. Bridge pattern.

Select an answer to check.

Answer: Wraps to add behavior.

The best option here is Wraps to add behavior.. Open/closed via composition. This matches the core idea being tested around which option best describes decorator in java. The other options are either incomplete or contextually incorrect.

Q34. What is the primary purpose of Decorator?

A. Adapter pattern. B. Bridge pattern. C. Replaces inheritance entirely. D. Wraps to add behavior.

Select an answer to check.

Answer: Wraps to add behavior.

For this question, Wraps to add behavior. is correct. Open/closed via composition. This matches the core idea being tested around what is the primary purpose of decorator. The other options are either incomplete or contextually incorrect.

Q35. Which statement about Decorator is most accurate?

A. Wraps to add behavior. B. Replaces inheritance entirely. C. Bridge pattern. D. Adapter pattern.

Select an answer to check.

Answer: Wraps to add behavior.

Wraps to add behavior. is the correct answer here. Open/closed via composition. This matches the core idea being tested around which statement about decorator is most accurate. The other options are either incomplete or contextually incorrect.

Q36. How is Decorator best characterized?

A. Wraps to add behavior. B. Adapter pattern. C. Replaces inheritance entirely. D. Bridge pattern.

Select an answer to check.

Answer: Wraps to add behavior.

Here, Wraps to add behavior. is the right choice. Open/closed via composition. That is exactly the concept behind how is decorator best characterized in this context. The other options are either incomplete or contextually incorrect.

Q37. Which option best describes Facade in Java?

A. Simplifies complex subsystems. B. Composite pattern. C. Bridge pattern. D. Adapter pattern.

Select an answer to check.

Answer: Simplifies complex subsystems.

In this case, Simplifies complex subsystems. is correct. Hides complexity. That is exactly the concept behind which option best describes facade in java in this context. The other options are either incomplete or contextually incorrect.

Q38. What is the primary purpose of Facade?

A. Simplifies complex subsystems. B. Bridge pattern. C. Adapter pattern. D. Composite pattern.

Select an answer to check.

Answer: Simplifies complex subsystems.

The best option here is Simplifies complex subsystems.. Hides complexity. That is exactly the concept behind what is the primary purpose of facade in this context. The other options are either incomplete or contextually incorrect.

Q39. Which statement about Facade is most accurate?

A. Composite pattern. B. Bridge pattern. C. Adapter pattern. D. Simplifies complex subsystems.

Select an answer to check.

Answer: Simplifies complex subsystems.

For this question, Simplifies complex subsystems. is correct. Hides complexity. That is exactly the concept behind which statement about facade is most accurate in this context. The other options are either incomplete or contextually incorrect.

Q40. How is Facade best characterized?

A. Composite pattern. B. Bridge pattern. C. Adapter pattern. D. Simplifies complex subsystems.

Select an answer to check.

Answer: Simplifies complex subsystems.

Simplifies complex subsystems. is the correct answer here. Hides complexity. That is exactly the concept behind how is facade best characterized in this context. The other options are either incomplete or contextually incorrect.

Q41. Which option best describes Flyweight in Java?

A. Pure caching only. B. Always allocate new. C. Share fine-grained objects. D. A pure singleton.

Select an answer to check.

Answer: Share fine-grained objects.

Here, Share fine-grained objects. is the right choice. Memory-saving with many objects. It fits the requirement in the prompt about which option best describes flyweight in java. The other options are either incomplete or contextually incorrect.

Q42. What is the primary purpose of Flyweight?

A. Always allocate new. B. Pure caching only. C. Share fine-grained objects. D. A pure singleton.

Select an answer to check.

Answer: Share fine-grained objects.

In this case, Share fine-grained objects. is correct. Memory-saving with many objects. It fits the requirement in the prompt about what is the primary purpose of flyweight. The other options are either incomplete or contextually incorrect.

Q43. Which statement about Flyweight is most accurate?

A. A pure singleton. B. Share fine-grained objects. C. Always allocate new. D. Pure caching only.

Select an answer to check.

Answer: Share fine-grained objects.

The best option here is Share fine-grained objects.. Memory-saving with many objects. It fits the requirement in the prompt about which statement about flyweight is most accurate. The other options are either incomplete or contextually incorrect.

Q44. How is Flyweight best characterized?

A. Always allocate new. B. Share fine-grained objects. C. Pure caching only. D. A pure singleton.

Select an answer to check.

Answer: Share fine-grained objects.

For this question, Share fine-grained objects. is correct. Memory-saving with many objects. It fits the requirement in the prompt about how is flyweight best characterized. The other options are either incomplete or contextually incorrect.

Q45. Which option best describes Proxy in Java?

A. A bridge. B. A facade only. C. An adapter only. D. Stand-in controlling access.

Select an answer to check.

Answer: Stand-in controlling access.

Stand-in controlling access. is the correct answer here. Lazy, security, remoting. It fits the requirement in the prompt about which option best describes proxy in java. The other options are either incomplete or contextually incorrect.

Q46. What is the primary purpose of Proxy?

A. A facade only. B. An adapter only. C. Stand-in controlling access. D. A bridge.

Select an answer to check.

Answer: Stand-in controlling access.

Here, Stand-in controlling access. is the right choice. Lazy, security, remoting. This is the most accurate statement for what is the primary purpose of proxy. The other options are either incomplete or contextually incorrect.

Q47. Which statement about Proxy is most accurate?

A. An adapter only. B. A facade only. C. A bridge. D. Stand-in controlling access.

Select an answer to check.

Answer: Stand-in controlling access.

In this case, Stand-in controlling access. is correct. Lazy, security, remoting. This is the most accurate statement for which statement about proxy is most accurate. The other options are either incomplete or contextually incorrect.

Q48. How is Proxy best characterized?

A. An adapter only. B. A facade only. C. A bridge. D. Stand-in controlling access.

Select an answer to check.

Answer: Stand-in controlling access.

The best option here is Stand-in controlling access.. Lazy, security, remoting. This is the most accurate statement for how is proxy best characterized. The other options are either incomplete or contextually incorrect.

Q49. Which option best describes Chain of Responsibility in Java?

A. Pass requests along a chain. B. Single handler always. C. An observer. D. A command.

Select an answer to check.

Answer: Pass requests along a chain.

For this question, Pass requests along a chain. is correct. Decouples sender and handler. This is the most accurate statement for which option best describes chain of responsibility in. The other options are either incomplete or contextually incorrect.

Q50. What is the primary purpose of Chain of Responsibility?

A. A command. B. An observer. C. Single handler always. D. Pass requests along a chain.

Select an answer to check.

Answer: Pass requests along a chain.

Pass requests along a chain. is the correct answer here. Decouples sender and handler. This is the most accurate statement for what is the primary purpose of chain of. The other options are either incomplete or contextually incorrect.