Interview Questions

1. What is the Order Of Execution of Destructors in Child and Parent Classes?

Options:

a. Child class destructor is executed first and then parent class destructor is executed.

b. Child class destructor is visited first but parent class destructor is executed first.

c. Parent class destructor is executed first and then child class destructor is executed.

d. None of the above

Reveal Answer

2. Can we use 'base' and 'this' in the same Constructor?

Options:

a. Yes

b. No

Reveal Answer

3. What is the advantage of inheritance?

Options:

a. Generalization

b. Extensibillity

c. Reusability

d. All the above

Reveal Answer

4. Does DOTNET support Multiple Inheritance?

Options:

a. Yes

b. No

Reveal Answer

5. What will be the output of the program? class CA { protected int M1=10; } class CB : CA { void Foo() { CA a = new CA(); Console.WriteLine( a.M1); } }

Options:

a. Compiletime error

b. Runtime Error

c. 10

d. 0

Reveal Answer

6. Inheritance between two classes is based on which of the relationship?

Options:

a. Is a

b. Has a

c. Instance of

d. Type of

Reveal Answer

7. Protected members are accessible only within the same class and in ________ .

Options:

a. Non-derived, and Derived

b. Only in Derived

c. Non-derived.

d. None of the above.

Reveal Answer

8. ) class CParent { public int PubA; private int PriA; protected int ProA; } class CChild:CParent { public int pubB; } When an object of CChild is created how many data members are allocated memory?

Options:

a. 3

b. 2

c. 4

d. 1

Reveal Answer

9. Which of the following is correct order of execution of constructor?

Options:

a. Child Class constructor first and then parent class

b. Parent class constructor first and then child class

c. Both will execute together.

d. Depending on the class intiantiaited.

Reveal Answer

10. class CA { public int PubA; private int PriA; protected int ProA; public CA(int a, int b, int c) { this.PriA = a; this.ProA = b; this.PubA = c; } } class CB : CA { public int pubB; public CB() : _____ { } } Fill in the above blank

Options:

a. base()

b. this()

c. this(1,2,3)

d. base(1,2,3)

Reveal Answer

11. class CA { public CA() { Console.WriteLine("In CA Default"); } public CA(int a, int b, int c) : this() { Console.WriteLine("In CA paremeterised"); } } class CB : CA { public CB() { Console.WriteLine("In CB Default"); } public CB(int a, int b, int c, int d) { Console.WriteLine("In CB Parameterised"); } } class Program { static void Main(string[] args) { CB a = new CB(1,2,3,4); } } What is the o/p?

Options:

a. In CA Default ,In CA Parameterised

b. In CA Default, In CA Parameterised , In CB Default, In CB Parameterised

c. In CA Default, In CB Parameterised

d. In CA Default , In CA Parameterised , In CB Parameterised

Reveal Answer

12. Parent p; Child c; c = new Parent();

Options:

a. Runtime Error

b. No Error

c. Compiler Error

Reveal Answer

13. Parent p; Child c; //...code to initialize both p and c c = p; p = c; Which of the above last two statements are valid c = p; p = c;

Options:

a. Both are valid

b. Both are invalid

Reveal Answer

14. What is the result of execution of below code Parent p = new Child() ; Child c = (Child) p;

Options:

a. No Error

b. Runtime Error

c. Compiler Error

Reveal Answer

15. What is the result of following code execution Parent p = new Parent(); Child c = (Child) p;

Options:

a. Compilation Error

b. Runtime error

c. No Error

Reveal Answer

16. What is the result of following code execution Parent p = new Parent(); Child c = p as Child;

Options:

a. Compilation Error

b. Runtime Error

c. No Error

Reveal Answer

17. What is the o/p of the following code: Parent p = new Parent(); Console.WriteLine(p is Child)

Options:

a. true

b. false

c. Parent

d. Child

Reveal Answer

18. What is the o/p of the below code: class CParent { public virtual void Foo() { Console.WriteLine("Parent"); } } class CChild : CParent { public override void Foo() { Console.WriteLine("Child"); } } class Program { static void Main(string[] args) { CParent a = new CChild(); a.Foo(); } }

Options:

a. Parent

b. Child

c. Child Parent

d. Parent Child

Reveal Answer

19. What is the o/p of the below code: class CParent { public virtual void Foo() { Console.WriteLine("Parent"); } } class CChild : CParent { public new void Foo() { Console.WriteLine("Child"); } } class Program { static void Main(string[] args) { CParent a = new CChild(); a.Foo(); } }

Options:

a. Parent Child Parent Child Child Parent

b. Child

c. Parent Child

d. Child Parent

Reveal Answer

20. What is the o/p of the below code: class CParent { public void Foo() { Console.WriteLine("Parent"); } } class CChild : CParent { public new void Foo() { Console.WriteLine("Child"); } } class Program { static void Main(string[] args) { CParent a = new CChild(); a.Foo(); } }

Options:

a. Parent

b. Child

c. Parent Child

d. Child Parent

Reveal Answer

21. class CA { public void Foo() { Console.WriteLine("CA"); } } class Program { static void Main(string[] args) { CA a = new CA(); a.Foo(); } }

Options:

a. Foo() is ________________ binding

b. static

c. dynamic

d. relative

Reveal Answer

22. Which of the following are true about the abstract class ?

Options:

a. Abstract class can have constructor and destructor

b. Abstract class can be instantiated

c. Abstract class can have non abstract methods

d. Abstract class must have at least one abstract methods

Reveal Answer

23. abstract class CA { public abstract void Foo(); } class CB:CA { public __________ void Foo() { } } Fill in the blank

Options:

a. override

b. new

c. either override or new

d. overrides

e. either override or new

Reveal Answer

24. Which of the following methods of Object class are not virtual

Options:

a. bool Equals(object obj)

b. System.Type GetType()

c. int GetHashCode()

d. string ToString()

Reveal Answer

25. Object is an abstract class and cannot be directly instantiated (true or false)

Options:

a. true

b. False

Reveal Answer

26. What is the result of below code class CA { public void Foo() { } } class Program { static void Main() { Object ob = new CA(); ob.Foo(); } }

Options:

a. Foo is invoked

b. Runtime Error

c. Compilation Error

d. ob cannot refer to object of class CA

Reveal Answer

Interview Questions and Answer

1. What is the Order Of Execution of Destructors in Child and Parent Classes?

2. Can we use 'base' and 'this' in the same Constructor?

3. What is the advantage of inheritance?

4. Does DOTNET support Multiple Inheritance?

5. What will be the output of the program? class CA { protected int M1=10; } class CB : CA { void Foo() { CA a = new CA(); Console.WriteLine( a.M1); } }

6. Inheritance between two classes is based on which of the relationship?

7. Protected members are accessible only within the same class and in ________ .

8. ) class CParent { public int PubA; private int PriA; protected int ProA; } class CChild:CParent { public int pubB; } When an object of CChild is created how many data members are allocated memory?

9. Which of the following is correct order of execution of constructor?

10. class CA { public int PubA; private int PriA; protected int ProA; public CA(int a, int b, int c) { this.PriA = a; this.ProA = b; this.PubA = c; } } class CB : CA { public int pubB; public CB() : _____ { } } Fill in the above blank

12. Parent p; Child c; c = new Parent();

13. Parent p; Child c; //...code to initialize both p and c c = p; p = c; Which of the above last two statements are valid c = p; p = c;

14. What is the result of execution of below code Parent p = new Child() ; Child c = (Child) p;

15. What is the result of following code execution Parent p = new Parent(); Child c = (Child) p;

16. What is the result of following code execution Parent p = new Parent(); Child c = p as Child;

17. What is the o/p of the following code: Parent p = new Parent(); Console.WriteLine(p is Child)

18. What is the o/p of the below code: class CParent { public virtual void Foo() { Console.WriteLine("Parent"); } } class CChild : CParent { public override void Foo() { Console.WriteLine("Child"); } } class Program { static void Main(string[] args) { CParent a = new CChild(); a.Foo(); } }

19. What is the o/p of the below code: class CParent { public virtual void Foo() { Console.WriteLine("Parent"); } } class CChild : CParent { public new void Foo() { Console.WriteLine("Child"); } } class Program { static void Main(string[] args) { CParent a = new CChild(); a.Foo(); } }

20. What is the o/p of the below code: class CParent { public void Foo() { Console.WriteLine("Parent"); } } class CChild : CParent { public new void Foo() { Console.WriteLine("Child"); } } class Program { static void Main(string[] args) { CParent a = new CChild(); a.Foo(); } }

21. class CA { public void Foo() { Console.WriteLine("CA"); } } class Program { static void Main(string[] args) { CA a = new CA(); a.Foo(); } }

22. Which of the following are true about the abstract class ?

23. abstract class CA { public abstract void Foo(); } class CB:CA { public __________ void Foo() { } } Fill in the blank

24. Which of the following methods of Object class are not virtual

25. Object is an abstract class and cannot be directly instantiated (true or false)

26. What is the result of below code class CA { public void Foo() { } } class Program { static void Main() { Object ob = new CA(); ob.Foo(); } }

Packages

Trending Certification Courses:

Microsoft Mock Exams:

Other links

About

Resources