Recently asked C++ interview questions

1. Why do we need to write Copy constructor when compiler provides a default Copy constructor?
2. What is conversion constructor?
3. What is difference between structure and class ?
4. Difference between stack and heap in terms of declared variables?
5. What are the advantages of new and delete over malloc and free?
6. What are differnt casting availble in C++ ?
7. What is upcasting and why upcasting is implicit in C++?
8. what happens to the memory alloted after the exception is raised???
9. How to declare a constant pointer and a pointer to constant variable
10. Describe how runtime polymorphism is achieved by the compliler?
11. explain the syntax (int* &i).
12. if we declare a class without any member variable and with out any function then what could be the size of such class ? Now if we declare only virtual function then what would be the size?
13. what is a register?
14. What is mutable data?
15. We have integer array which is having repeated entries i.e. arr[] = {1,2,2,2,3,3,4,5,5,6,4,1} Write an optimum code to get the unique value?
16. Write the code to insert a node in sorted doubly linked list
17. Write your own printf() function?
18. What is a conversion operator?
19. Take the example of traffic and explain polymorphism ( not in C++ terminology)