If you’re gearing up for tech interviews, you might want to brush up a little on C++. C++ is among the most popular languages for system programming, game development, embedded systems, and even fintech. This document discusses the most relevant C++ Coding Interview Questions and Answers, set in a relaxed yet informal tone in order to relieve the anxiety of students and working people preparing for an interview. So let’s get going.
What Is the Importance of C++ Coding Interview Questions?
Whether you are a fresh graduate or changing jobs after several years of experience, the interviewers tend to grill you on the basics of C++ memory management, object-oriented programming, and standard template libraries (STL). C++ Coding Interview Questions test not only your syntax skills but also your problem-solving and logical skills. Practice makes perfect, so take all the practice you can get.
Basics First: Introductory C++ Coding Interview Questions and Answers
1. What is C++?
C++ is a general-purpose programming language whose main intention includes both procedures and object orientation in programming. It is most commonly used to do system programming because it is better known for performance and access at the system level.
2. Which are the basic data types that C++ possesses?
Commonly used data types are int, float, double, char, bool, and void.
3. What is the difference between C and C++?
C++ supports OOP, whereas C does not. It allows classes, inheritance, and enables polymorphism.
4. Define class and object for C++
A class is a blueprint, while an object is a variable made through this.
5. What is the use of a namespace in C++?
Namespaces are used to override name conflicts while working with large projects.
Going on these C++ Coding Interview Questions and Answers, you would cover the strong basics before you delve into the advanced topics.
Intermediate C++ Coding Interview Questions and Answers
6. What is the difference between ‘new’ and “malloc”?
‘new’ is an operator in C++ and by calling it the constructor is invoked; malloc does nothing other than allocate memory in C language.
7. What do you mean by constructor overloading?
More than one constructor in a class with different types or numbers of parameters is constructor overloading.
8. What is function overloading in C++?
It allows defining more than one function holding the same name with different parameters.
9. What do you mean by virtual function?
A function which is to be overridden specifically in derived class, allowing for run time polymorphism.
10. What is the significance of the ‘this’ pointer?
This points to the object currently invoking the function of the defined class.
You will often find these C++ Coding Interview Questions and Answers when interviewers wish to check your understanding of object orientation principles.
Advanced Concepts in C++ Coding Interview Questions
11. Meaning of inheritance in C++:
Inheritance lets one class (the derived) acquire properties and behaviors from another class (the base).
12. What are the different categories of inheritance in C++?
Single, multiple, multilevel, hierarchical inheritance, and hybrid.
13. What is multiple inheritance?
Whenever a class can inherit from more than one base class.
14. What is encapsulation?
Encapsulation binds the data and methods together into a single unit.
15. What is abstraction in C++?
Abstraction means the inclusion of the most essential information and maintenance of hidden complex implementation details.
These C++ Coding Interview Questions and Answers would help you define the concepts defining the object-oriented flavor of C++.
Memory Management: C++ Coding Interview Questions and Answers You Must Not Miss
16. What do you mean by a memory leak?
A memory leak occurs when a portion of memory allocated to an object is not returned back to the system after the object is no longer in use.
17. How can one prevent memory leaks?
By smart pointers or by ensuring explicit deletion of allocated memory.
18. What is meant by a dangling pointer?
A dangling pointer refers to a pointer which points to a freed memory.
19. What is the role of ‘delete’ and ‘delete[]’?
Delete releases the memory allocated for a single object. Delete[] is related to arrays.
20. What are smart pointers in C++?
Smart pointers serve as memory-management tools that follow RAII.
You can expect these types of C++ coding interview questions related to memory safety and smart resource management when attending interviews in product-based companies.
STL centered C++ Coding Interview Question and Answers
21. What is STL in C++?
The Standard Template Library provides ready-to-use classes and functions such as vectors, stacks, queues, and maps.
22. What is the difference between vector to array?
On the contrary, vector is capable of resizing by itself, unlike arrays.
23. What are iterators in STL?
Iterators are objects which point to the elements of a container.
24. What is the use of a map in C++ STL?
Maps maintain key-value pairs and sort the keys automatically.
25. Difference between unordered_map and map?
Uses hashing in contrast with unordered_map, while map maintains the order.
STL is a sunshine subject for interviewers so do keep a fair share of C++ Coding Interview Questions and Answers on this.
Pointers and References – C++ Coding Interview Questions and Answers
26. What is the difference between pointer and reference?
Pointer’s value can be changed; a reference’s value cannot.
27. What is pointer arithmetic?
Pointer arithmetic means that you can perform operations such as addition or subtraction on pointers.
28. What is NULL pointer?
A pointer that does not point to any memory location.
29. What are wild pointers?
Pointers that are uninitialized and may point to any memory.
30. What is a reference variable?
Alias of another variable.
These C++ Coding Interview Questions are most common when testing your understanding of the low-level features of C++.
C++ Coding Interview Questions Asked Frequently in Product Companies
31. What is deep copy and shallow copy?
Deep copy duplicates actual memory, shallow copy references.
32. Explain RAII (Resource Acquisition Is Initialization).
A design pattern where resource allocation is tied to object lifetime.
33. What is the role of the static keyword in C++?
Static memory means retainability of value across function calls and restricts access of functions to a file.
34. What is the use of “mutable” keyword?
This allows a member of an object to be modified even if the object is declared const.
35. What are friend functions?
Non-member functions that have access to private members.
These C++ Coding Interview Questions and Answers often separate a beginner visitor from an experienced one who faces top-tier companies.
Tricky C++ Coding Interview Questions with Real-World Cases
36. How is exception handling in C++?
Using try, catch, and throw keywords.
37. What happens if a constructor throws an exception?
Then the object is not created, and the destructor is not called.
38. Can we override private methods?
No, private methods are not accessible in derived classes.
39. Can a constructor be virtual?
No, constructor cannot be virtual.
40. Why destructors are declared virtual in base classes?
For the proper cleanup of derived objects by base class pointers.
These C++ Coding Interviews Questions and Answers are the curves that you are supposed to prepare for.
The Bonus Real 10 C++ Coding Interview Questions and Answers for Self Practice:
41. Difference between stack and heap memory in C++?
42. The preprocessor stands in C++.
43. Can we call a virtual function from a constructor?
44. What is pure virtual function?
45. How polymorphism is achieved in C++?
46. Explain static and dynamic binding.
47. What is an inline function?
48. What is typecasting in C++?
49. What is the difference between struct and class in C++?
50. What is the scope resolution operator?
These are the last C++ Coding Interview Questions and Answers, regarding edge cases or even theories-perhaps perfect to cap your study.
Real Practice on C++ Coding Interview Questions
To clear technical interviews, one needs to practice these C++ real-world Coding Interview Questions and Answers. It must not only be read but also implemented, tweaked and the code run. It builds muscle memory. Whether a student preparing for campus placement or an employee looking for alternate opportunities, these questions will take one a long way.
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