25 questions on Programming Practices (C++)

 25 questions on Programming Practices (C++) along with answers:

Questions and Answers:

1. What is the main difference between C and C++?

   • C++ supports object-oriented programming, while C is procedural.

2. Explain encapsulation in C++.

   • Encapsulation restricts access to certain class components, bundling data with functions.

3. What is inheritance in C++?

   • Inheritance allows one class to acquire the properties of another, enabling code reuse.

4. What is polymorphism in C++?

   • Polymorphism enables functions or operators to behave differently based on context (e.g., overloading).

5. Define constructor and destructor in C++.

   • Constructors initialize objects; destructors clean up resources when objects go out of scope.

6. What is operator overloading?

   • Operator overloading allows operators to work with user-defined types.

7. Explain what a virtual function is in C++.

   • A virtual function allows derived classes to override a function defined in the base class.

8. What is a pure virtual function?

   • A pure virtual function is declared in a base class with = 0, making the class abstract.

9. Explain the concept of namespaces in C++.

   • Namespaces prevent naming conflicts by organizing code into distinct areas.

10. What is the this pointer?

    • this is a pointer to the current object instance, used within class methods.

11. Define function overloading.

    • Function overloading allows multiple functions with the same name but different parameters.

12. What is the purpose of friend keyword in C++?

    • friend allows a function or another class to access private members of a class.

13. Explain the static keyword in C++.

    • static variables retain their value between function calls and are shared by all instances of a class.

14. What is an exception in C++?

    • An exception is an error that occurs during execution; it’s handled with try, catch, and throw.

15. Define the concept of dynamic memory allocation in C++.

    • Dynamic memory is allocated during runtime using new and deallocated with delete.

16. What are templates in C++?

    • Templates allow generic programming by creating functions or classes to work with any data type.

17. What is the difference between struct and class in C++?

    • By default, struct members are public, while class members are private.

18. Explain what a copy constructor is.

    • A copy constructor creates a new object as a copy of an existing object.

19. What is a function pointer?

    • A function pointer stores the address of a function, allowing dynamic function calls.

20. Explain the role of the const keyword.

    • const defines constants, preventing variables from being modified after initialization.

21. What are standard template library (STL) containers?

    • STL containers like vector, list, map, and set store collections of data.

22. What is the difference between ++i and i++?

    • ++i increments i before returning it; i++ increments after returning the original i.

23. Explain type casting in C++.

    • Type casting converts one data type to another using static_cast, dynamic_cast, const_cast, and reinterpret_cast.

24. What is a lambda function in C++?

    • Lambda functions are anonymous functions defined with [] for use in-line.

25. What is the purpose of a move constructor?

    • A move constructor transfers resources from a temporary object to a new object, avoiding deep copies.

Let me know if you need more in-depth explanations or examples for any of these!