Typical C++ interview questions sorted by experience

Typical C++ interview questions sorted by experience

Junior:

- What are the key features of object-oriented programming in C++?

- Explain the differences between public, private, and protected access specifiers in C++.

- Distinguish between function overloading and overriding in C++.

- Compare and contrast abstract classes and interfaces in C++.

- Can an interface inherit from another interface in C++?

- Define the static keyword in C++ and its significance.

- Is it possible to override a static method in C++?

- Explain the concepts of polymorphism and inheritance in C++.

- Can constructors be inherited in C++?

- Discuss pass-by-reference and pass-by-value for objects in C++.

- Compare == and .equals for string comparison in C++.

- Explain the purposes of the hashCode() and equals() functions.

- What does the Serializable interface do? How is it related to Parcelable in Android?

- Differentiate between Array and ArrayList in C++. When would you use each?

- Explain the distinction between Integer and int in C++.

- Define ThreadPool and discuss its advantages over using simple threads.

- Differentiate between local, instance, and class variables in C++.

Mid:

- What is reflection in C++?

- Define dependency injection and name a few libraries. Have you used any?

- Explain strong, soft, and weak references in C++.

- Interpret the meaning of the synchronized keyword.

- Can memory leaks occur in C++?

- Is it necessary to set references to null in C++?

- Why is a String considered immutable?

- Discuss transient and volatile modifiers in C++.

- What is the purpose of the finalize() method?

- How does the try{} finally{} block work in C++?

- Explain the difference between object instantiation and initialization.

- Under what conditions is a static block executed in C++?

- Why are generics used in C++?

- Mention some design patterns you are familiar with. Which do you typically use?

- Name some types of testing methodologies in C++.

Senior:

- Explain how std::stoi (string to integer) works in C++.

- What is the "double-check locking" problem, and how can it be solved in C++?

- Differentiate between StringBuffer and StringBuilder in C++.

- How is StringBuilder implemented to avoid the immutable string allocation problem?

- Explain the purpose of the Class.forName method in C++.

- Define Autoboxing and Unboxing in C++.

- What's the difference between Enumeration and Iterator in C++?

- Explain the difference between fail-fast and fail-safe in C++.

- What is PermGen in C++?

- Describe a Java priority queue.

- How is performance influenced by using the same number in different types: Int, Double, and Float?

- Explain the concept of the Java Heap.

- What is a daemon thread?

- Can a dead thread be restarted in C++?

Here are some interview preparation tips 👇👇

Technical Interview

1. Review Core Concepts:

  - Data Structures: Be comfortable with LinkedLists, Trees, Graphs, and their representations.

  - Algorithms: Brush up on searching and sorting algorithms, time complexities, and common algorithms (like Dijkstra’s or A*).

  - Programming Languages: Ensure you understand the language you are most comfortable with (e.g., C++, Java, Python) and know its standard library functions.

2. Practice Coding Problems:

  - Utilize platforms like LeetCode, HackerRank, or CodeSignal to practice medium-level coding questions. Focus on common patterns and problem-solving strategies.

3. Mock Interviews: Conduct mock technical interviews with peers or mentors to build confidence and receive feedback.

Personal Interview

1. Prepare Your Story:

  - Outline your educational journey, achievements, and any relevant projects. Emphasize experiences that demonstrate leadership, teamwork, and problem-solving skills.

  - Be ready to discuss your challenges and how you overcame them.

2. Articulate Your Goals:

  - Be clear about why you want to join the program and how it aligns with your career aspirations. Reflect on what you hope to gain from the experience.

- Focus on Fundamentals:

Be thorough with basic subjects like Operating Systems, Networking, OOP, and Databases. Clear concepts are key for technical interviews.

2. Common Interview Questions:

DSA:

- Implement various data structures like Linked Lists, Trees, Graphs, Stacks, and Queues.

- Understand searching and sorting algorithms: Binary Search, Merge Sort, Quick Sort, etc.

- Solve problems involving HashMaps, Sets, and other collections.

Sample DSA Questions

- Reverse a linked list.

- Find the first non-repeating character in a string.

- Detect a cycle in a graph.

- Implement a queue using two stacks.

- Find the lowest common ancestor in a binary tree.

3. Key Topics to Focus On

DSA:

- Arrays, Strings, Linked Lists, Trees, Graphs

- Recursion, Backtracking, Dynamic Programming

- Sorting and Searching Algorithms

- Time and Space Complexity

Core Subjects

- Operating Systems: Concepts like processes, threads, deadlocks, concurrency, and memory management.

- Database Management Systems (DBMS): Understanding SQL, Normalization, and database design.

- Object-Oriented Programming (OOP): Know about inheritance, polymorphism, encapsulation, and design patterns.

5. Tips

- Optimize Your Code: Write clean, optimized code. Discuss time and space complexities during interviews.

- Review Your Projects: Be ready to explain your past projects, the challenges you faced, and the technologies you used