C# Generics MCQ Questions with Answers (Latest 2026)

Q1. Which option best describes a generic class in C#/.NET?

A. A class parameterized by type, e.g., List<T>. B. A non-parameterized class. C. A delegate. D. An attribute.

Select an answer to check.

Answer: A class parameterized by type, e.g., List<T>.

Here, A class parameterized by type, e.g., List<T>. is the right choice. Type safety with reuse. It aligns directly with what the question asks about which option best describes a generic class in. A quick elimination of partially true options helps confirm it.

Q2. What is the primary purpose of a generic class?

A. A class parameterized by type, e.g., List<T>. B. A non-parameterized class. C. A delegate. D. An attribute.

Select an answer to check.

Answer: A class parameterized by type, e.g., List<T>.

In this case, A class parameterized by type, e.g., List<T>. is correct. Type safety with reuse. It aligns directly with what the question asks about what is the primary purpose of a generic. A quick elimination of partially true options helps confirm it.

Q3. Which statement about a generic class is most accurate?

A. An attribute. B. A class parameterized by type, e.g., List<T>. C. A non-parameterized class. D. A delegate.

Select an answer to check.

Answer: A class parameterized by type, e.g., List<T>.

The best option here is A class parameterized by type, e.g., List<T>.. Type safety with reuse. It aligns directly with what the question asks about which statement about a generic class is most. A quick elimination of partially true options helps confirm it.

Q4. How is a generic class best characterized?

A. An attribute. B. A delegate. C. A non-parameterized class. D. A class parameterized by type, e.g., List<T>.

Select an answer to check.

Answer: A class parameterized by type, e.g., List<T>.

For this question, A class parameterized by type, e.g., List<T>. is correct. Type safety with reuse. It aligns directly with what the question asks about how is a generic class best characterized. A quick elimination of partially true options helps confirm it.

Q5. Which option best describes a generic method in C#/.NET?

A. An attribute. B. A static helper only. C. A constructor. D. A method parameterized by type.

Select an answer to check.

Answer: A method parameterized by type.

A method parameterized by type. is the correct answer here. Type inferred from args often. It aligns directly with what the question asks about which option best describes a generic method in. A quick elimination of partially true options helps confirm it.

Q6. What is the primary purpose of a generic method?

A. A constructor. B. An attribute. C. A static helper only. D. A method parameterized by type.

Select an answer to check.

Answer: A method parameterized by type.

Here, A method parameterized by type. is the right choice. Type inferred from args often. This matches the core idea being tested around what is the primary purpose of a generic. A quick elimination of partially true options helps confirm it.

Q7. Which statement about a generic method is most accurate?

A. An attribute. B. A static helper only. C. A constructor. D. A method parameterized by type.

Select an answer to check.

Answer: A method parameterized by type.

In this case, A method parameterized by type. is correct. Type inferred from args often. This matches the core idea being tested around which statement about a generic method is most. A quick elimination of partially true options helps confirm it.

Q8. How is a generic method best characterized?

A. A static helper only. B. A constructor. C. An attribute. D. A method parameterized by type.

Select an answer to check.

Answer: A method parameterized by type.

The best option here is A method parameterized by type.. Type inferred from args often. This matches the core idea being tested around how is a generic method best characterized. A quick elimination of partially true options helps confirm it.

Q9. Which option best describes type parameter in C#/.NET?

A. An attribute. B. A field. C. A reflection symbol only. D. Placeholder type T used in generic definitions.

Select an answer to check.

Answer: Placeholder type T used in generic definitions.

For this question, Placeholder type T used in generic definitions. is correct. Names like T, TKey, TValue. This matches the core idea being tested around which option best describes type parameter in c#/.net. A quick elimination of partially true options helps confirm it.

Q10. What is the primary purpose of type parameter?

A. An attribute. B. A reflection symbol only. C. A field. D. Placeholder type T used in generic definitions.

Select an answer to check.

Answer: Placeholder type T used in generic definitions.

Placeholder type T used in generic definitions. is the correct answer here. Names like T, TKey, TValue. This matches the core idea being tested around what is the primary purpose of type parameter. A quick elimination of partially true options helps confirm it.

Q11. Which statement about type parameter is most accurate?

A. An attribute. B. A field. C. A reflection symbol only. D. Placeholder type T used in generic definitions.

Select an answer to check.

Answer: Placeholder type T used in generic definitions.

Here, Placeholder type T used in generic definitions. is the right choice. Names like T, TKey, TValue. That is exactly the concept behind which statement about type parameter is most accurate in this context. A quick elimination of partially true options helps confirm it.

Q12. How is type parameter best characterized?

A. A reflection symbol only. B. An attribute. C. A field. D. Placeholder type T used in generic definitions.

Select an answer to check.

Answer: Placeholder type T used in generic definitions.

In this case, Placeholder type T used in generic definitions. is correct. Names like T, TKey, TValue. That is exactly the concept behind how is type parameter best characterized in this context. A quick elimination of partially true options helps confirm it.

Q13. Which option best describes type constraint in C#/.NET?

A. A boxing operation. B. A runtime cast only. C. A compile-time attribute only. D. Restrictions like where T : class, struct, new(), interface.

Select an answer to check.

Answer: Restrictions like where T : class, struct, new(), interface.

The best option here is Restrictions like where T : class, struct, new(), interface.. Compiler enforces. That is exactly the concept behind which option best describes type constraint in c#/.net in this context. A quick elimination of partially true options helps confirm it.

Q14. What is the primary purpose of type constraint?

A. A runtime cast only. B. Restrictions like where T : class, struct, new(), interface. C. A compile-time attribute only. D. A boxing operation.

Select an answer to check.

Answer: Restrictions like where T : class, struct, new(), interface.

For this question, Restrictions like where T : class, struct, new(), interface. is correct. Compiler enforces. That is exactly the concept behind what is the primary purpose of type constraint in this context. A quick elimination of partially true options helps confirm it.

Q15. Which statement about type constraint is most accurate?

A. A boxing operation. B. A compile-time attribute only. C. Restrictions like where T : class, struct, new(), interface. D. A runtime cast only.

Select an answer to check.

Answer: Restrictions like where T : class, struct, new(), interface.

Restrictions like where T : class, struct, new(), interface. is the correct answer here. Compiler enforces. That is exactly the concept behind which statement about type constraint is most accurate in this context. A quick elimination of partially true options helps confirm it.

Q16. How is type constraint best characterized?

A. A boxing operation. B. Restrictions like where T : class, struct, new(), interface. C. A compile-time attribute only. D. A runtime cast only.

Select an answer to check.

Answer: Restrictions like where T : class, struct, new(), interface.

Here, Restrictions like where T : class, struct, new(), interface. is the right choice. Compiler enforces. It fits the requirement in the prompt about how is type constraint best characterized. A quick elimination of partially true options helps confirm it.

Q17. Which option best describes where T : class in C#/.NET?

A. T must be a struct. B. T must implement IDisposable. C. T must be sealed. D. T must be a reference type.

Select an answer to check.

Answer: T must be a reference type.

In this case, T must be a reference type. is correct. Reference type constraint. It fits the requirement in the prompt about which option best describes where t : class. A quick elimination of partially true options helps confirm it.

Q18. What is the primary purpose of where T : class?

A. T must implement IDisposable. B. T must be a struct. C. T must be a reference type. D. T must be sealed.

Select an answer to check.

Answer: T must be a reference type.

The best option here is T must be a reference type.. Reference type constraint. It fits the requirement in the prompt about what is the primary purpose of where t. A quick elimination of partially true options helps confirm it.

Q19. Which statement about where T : class is most accurate?

A. T must be sealed. B. T must be a reference type. C. T must implement IDisposable. D. T must be a struct.

Select an answer to check.

Answer: T must be a reference type.

For this question, T must be a reference type. is correct. Reference type constraint. It fits the requirement in the prompt about which statement about where t : class is. A quick elimination of partially true options helps confirm it.

Q20. How is where T : class best characterized?

A. T must be sealed. B. T must be a reference type. C. T must be a struct. D. T must implement IDisposable.

Select an answer to check.

Answer: T must be a reference type.

T must be a reference type. is the correct answer here. Reference type constraint. It fits the requirement in the prompt about how is where t : class best characterized. A quick elimination of partially true options helps confirm it.

Q21. Which option best describes where T : struct in C#/.NET?

A. T must be a class. B. T must be sealed. C. T must be a non-nullable value type. D. T must be public.

Select an answer to check.

Answer: T must be a non-nullable value type.

Here, T must be a non-nullable value type. is the right choice. Value type constraint. This is the most accurate statement for which option best describes where t : struct. A quick elimination of partially true options helps confirm it.

Q22. What is the primary purpose of where T : struct?

A. T must be public. B. T must be a class. C. T must be a non-nullable value type. D. T must be sealed.

Select an answer to check.

Answer: T must be a non-nullable value type.

In this case, T must be a non-nullable value type. is correct. Value type constraint. This is the most accurate statement for what is the primary purpose of where t. A quick elimination of partially true options helps confirm it.

Q23. Which statement about where T : struct is most accurate?

A. T must be public. B. T must be a non-nullable value type. C. T must be sealed. D. T must be a class.

Select an answer to check.

Answer: T must be a non-nullable value type.

The best option here is T must be a non-nullable value type.. Value type constraint. This is the most accurate statement for which statement about where t : struct is. A quick elimination of partially true options helps confirm it.

Q24. How is where T : struct best characterized?

A. T must be public. B. T must be a class. C. T must be a non-nullable value type. D. T must be sealed.

Select an answer to check.

Answer: T must be a non-nullable value type.

For this question, T must be a non-nullable value type. is correct. Value type constraint. This is the most accurate statement for how is where t : struct best characterized. A quick elimination of partially true options helps confirm it.

Q25. Which option best describes where T : new() in C#/.NET?

A. T must implement IComparable. B. T must be sealed. C. T must be abstract. D. T must have a public parameterless constructor.

Select an answer to check.

Answer: T must have a public parameterless constructor.

T must have a public parameterless constructor. is the correct answer here. Used to instantiate T inside method. This is the most accurate statement for which option best describes where t : new(). A quick elimination of partially true options helps confirm it.

Q26. What is the primary purpose of where T : new()?

A. T must be sealed. B. T must implement IComparable. C. T must be abstract. D. T must have a public parameterless constructor.

Select an answer to check.

Answer: T must have a public parameterless constructor.

Here, T must have a public parameterless constructor. is the right choice. Used to instantiate T inside method. It aligns directly with what the question asks about what is the primary purpose of where t. The other options are either incomplete or contextually incorrect.

Q27. Which statement about where T : new() is most accurate?

A. T must implement IComparable. B. T must be sealed. C. T must have a public parameterless constructor. D. T must be abstract.

Select an answer to check.

Answer: T must have a public parameterless constructor.

In this case, T must have a public parameterless constructor. is correct. Used to instantiate T inside method. It aligns directly with what the question asks about which statement about where t : new() is. The other options are either incomplete or contextually incorrect.

Q28. How is where T : new() best characterized?

A. T must be sealed. B. T must have a public parameterless constructor. C. T must be abstract. D. T must implement IComparable.

Select an answer to check.

Answer: T must have a public parameterless constructor.

The best option here is T must have a public parameterless constructor.. Used to instantiate T inside method. It aligns directly with what the question asks about how is where t : new() best characterized. The other options are either incomplete or contextually incorrect.

Q29. Which option best describes where T : IComparable<T> in C#/.NET?

A. T must be struct. B. T must be class. C. T must be IDisposable. D. T must be comparable to itself.

Select an answer to check.

Answer: T must be comparable to itself.

For this question, T must be comparable to itself. is correct. Allows comparison operations. It aligns directly with what the question asks about which option best describes where t : icomparable<t>. The other options are either incomplete or contextually incorrect.

Q30. What is the primary purpose of where T : IComparable<T>?

A. T must be comparable to itself. B. T must be class. C. T must be IDisposable. D. T must be struct.

Select an answer to check.

Answer: T must be comparable to itself.

T must be comparable to itself. is the correct answer here. Allows comparison operations. It aligns directly with what the question asks about what is the primary purpose of where t. The other options are either incomplete or contextually incorrect.

Q31. Which statement about where T : IComparable<T> is most accurate?

A. T must be IDisposable. B. T must be struct. C. T must be class. D. T must be comparable to itself.

Select an answer to check.

Answer: T must be comparable to itself.

Here, T must be comparable to itself. is the right choice. Allows comparison operations. This matches the core idea being tested around which statement about where t : icomparable<t> is. The other options are either incomplete or contextually incorrect.

Q32. How is where T : IComparable<T> best characterized?

A. T must be IDisposable. B. T must be comparable to itself. C. T must be class. D. T must be struct.

Select an answer to check.

Answer: T must be comparable to itself.

In this case, T must be comparable to itself. is correct. Allows comparison operations. This matches the core idea being tested around how is where t : icomparable<t> best characterized. The other options are either incomplete or contextually incorrect.

Q33. Which option best describes covariance in C#/.NET?

A. Always invariance. B. Variance with classes only. C. IEnumerable<Derived> assignable to IEnumerable<Base>. D. Always contravariance.

Select an answer to check.

Answer: IEnumerable<Derived> assignable to IEnumerable<Base>.

The best option here is IEnumerable<Derived> assignable to IEnumerable<Base>.. Out parameter on interface. This matches the core idea being tested around which option best describes covariance in c#/.net. The other options are either incomplete or contextually incorrect.

Q34. What is the primary purpose of covariance?

A. Variance with classes only. B. Always contravariance. C. IEnumerable<Derived> assignable to IEnumerable<Base>. D. Always invariance.

Select an answer to check.

Answer: IEnumerable<Derived> assignable to IEnumerable<Base>.

For this question, IEnumerable<Derived> assignable to IEnumerable<Base>. is correct. Out parameter on interface. This matches the core idea being tested around what is the primary purpose of covariance. The other options are either incomplete or contextually incorrect.

Q35. Which statement about covariance is most accurate?

A. Always invariance. B. Variance with classes only. C. Always contravariance. D. IEnumerable<Derived> assignable to IEnumerable<Base>.

Select an answer to check.

Answer: IEnumerable<Derived> assignable to IEnumerable<Base>.

IEnumerable<Derived> assignable to IEnumerable<Base>. is the correct answer here. Out parameter on interface. This matches the core idea being tested around which statement about covariance is most accurate. The other options are either incomplete or contextually incorrect.

Q36. How is covariance best characterized?

A. Always contravariance. B. IEnumerable<Derived> assignable to IEnumerable<Base>. C. Variance with classes only. D. Always invariance.

Select an answer to check.

Answer: IEnumerable<Derived> assignable to IEnumerable<Base>.

Here, IEnumerable<Derived> assignable to IEnumerable<Base>. is the right choice. Out parameter on interface. That is exactly the concept behind how is covariance best characterized in this context. The other options are either incomplete or contextually incorrect.

Q37. Which option best describes contravariance in C#/.NET?

A. Invariance only. B. Action<Base> assignable to Action<Derived>. C. Pure inheritance only. D. Covariance only.

Select an answer to check.

Answer: Action<Base> assignable to Action<Derived>.

In this case, Action<Base> assignable to Action<Derived>. is correct. In parameter on interface/delegate. That is exactly the concept behind which option best describes contravariance in c#/.net in this context. The other options are either incomplete or contextually incorrect.

Q38. What is the primary purpose of contravariance?

A. Pure inheritance only. B. Invariance only. C. Action<Base> assignable to Action<Derived>. D. Covariance only.

Select an answer to check.

Answer: Action<Base> assignable to Action<Derived>.

The best option here is Action<Base> assignable to Action<Derived>.. In parameter on interface/delegate. That is exactly the concept behind what is the primary purpose of contravariance in this context. The other options are either incomplete or contextually incorrect.

Q39. Which statement about contravariance is most accurate?

A. Action<Base> assignable to Action<Derived>. B. Invariance only. C. Covariance only. D. Pure inheritance only.

Select an answer to check.

Answer: Action<Base> assignable to Action<Derived>.

For this question, Action<Base> assignable to Action<Derived>. is correct. In parameter on interface/delegate. That is exactly the concept behind which statement about contravariance is most accurate in this context. The other options are either incomplete or contextually incorrect.

Q40. How is contravariance best characterized?

A. Pure inheritance only. B. Action<Base> assignable to Action<Derived>. C. Invariance only. D. Covariance only.

Select an answer to check.

Answer: Action<Base> assignable to Action<Derived>.

Action<Base> assignable to Action<Derived>. is the correct answer here. In parameter on interface/delegate. That is exactly the concept behind how is contravariance best characterized in this context. The other options are either incomplete or contextually incorrect.

Q41. Which option best describes invariance in C#/.NET?

A. Default: List<Derived> not assignable to List<Base>. B. Free assignment always. C. Contravariance always. D. Covariance always.

Select an answer to check.

Answer: Default: List<Derived> not assignable to List<Base>.

Here, Default: List<Derived> not assignable to List<Base>. is the right choice. C# generics are invariant by default. It fits the requirement in the prompt about which option best describes invariance in c#/.net. The other options are either incomplete or contextually incorrect.

Q42. What is the primary purpose of invariance?

A. Free assignment always. B. Contravariance always. C. Default: List<Derived> not assignable to List<Base>. D. Covariance always.

Select an answer to check.

Answer: Default: List<Derived> not assignable to List<Base>.

In this case, Default: List<Derived> not assignable to List<Base>. is correct. C# generics are invariant by default. It fits the requirement in the prompt about what is the primary purpose of invariance. The other options are either incomplete or contextually incorrect.

Q43. Which statement about invariance is most accurate?

A. Default: List<Derived> not assignable to List<Base>. B. Free assignment always. C. Covariance always. D. Contravariance always.

Select an answer to check.

Answer: Default: List<Derived> not assignable to List<Base>.

The best option here is Default: List<Derived> not assignable to List<Base>.. C# generics are invariant by default. It fits the requirement in the prompt about which statement about invariance is most accurate. The other options are either incomplete or contextually incorrect.

Q44. How is invariance best characterized?

A. Contravariance always. B. Default: List<Derived> not assignable to List<Base>. C. Free assignment always. D. Covariance always.

Select an answer to check.

Answer: Default: List<Derived> not assignable to List<Base>.

For this question, Default: List<Derived> not assignable to List<Base>. is correct. C# generics are invariant by default. It fits the requirement in the prompt about how is invariance best characterized. The other options are either incomplete or contextually incorrect.

Q45. Which option best describes List<T> in C#/.NET?

A. Dictionary of T. B. Resizable array of T. C. Linked list of T. D. HashSet of T.

Select an answer to check.

Answer: Resizable array of T.

Resizable array of T. is the correct answer here. Common general-purpose collection. It fits the requirement in the prompt about which option best describes list<t> in c#/.net. The other options are either incomplete or contextually incorrect.

Q46. What is the primary purpose of List<T>?

A. Linked list of T. B. Dictionary of T. C. HashSet of T. D. Resizable array of T.

Select an answer to check.

Answer: Resizable array of T.

Here, Resizable array of T. is the right choice. Common general-purpose collection. This is the most accurate statement for what is the primary purpose of list<t>. The other options are either incomplete or contextually incorrect.

Q47. Which statement about List<T> is most accurate?

A. HashSet of T. B. Linked list of T. C. Dictionary of T. D. Resizable array of T.

Select an answer to check.

Answer: Resizable array of T.

In this case, Resizable array of T. is correct. Common general-purpose collection. This is the most accurate statement for which statement about list<t> is most accurate. The other options are either incomplete or contextually incorrect.

Q48. How is List<T> best characterized?

A. HashSet of T. B. Resizable array of T. C. Linked list of T. D. Dictionary of T.

Select an answer to check.

Answer: Resizable array of T.

The best option here is Resizable array of T.. Common general-purpose collection. This is the most accurate statement for how is list<t> best characterized. The other options are either incomplete or contextually incorrect.

Q49. Which option best describes Dictionary<TKey,TValue> in C#/.NET?

A. A list of tuples only. B. A queue. C. A linked list. D. Hash map from key to value.

Select an answer to check.

Answer: Hash map from key to value.

For this question, Hash map from key to value. is correct. Average O(1) operations. This is the most accurate statement for which option best describes dictionary<tkey,tvalue> in c#/.net. The other options are either incomplete or contextually incorrect.

Q50. What is the primary purpose of Dictionary<TKey,TValue>?

A. A list of tuples only. B. A linked list. C. Hash map from key to value. D. A queue.

Select an answer to check.

Answer: Hash map from key to value.

Hash map from key to value. is the correct answer here. Average O(1) operations. This is the most accurate statement for what is the primary purpose of dictionary<tkey,tvalue>. The other options are either incomplete or contextually incorrect.