C++ 인터뷰 준비하기 - 1. Basic Concepts

이번에 C++ 인터뷰를 준비하면서 예상 질문 리스트를 만들어봤다. 이걸 블로그에 공유해볼까 한다.

영어 인터뷰였기 때문에 질문과 답변도 영어로 작성되어 있다.

내가 본 인터뷰의 후기를 간단히 말하자면, C++ 관련 질문은 경험이 있다면 쉽게 대답할 수 있는 내용이 많았지만, 오히려 다른 전공 도메인 관련 질문이 더 까다로웠다... 🥲

실제로 받았던 질문에는 형광펜 표시를 해서 따로 강조해 보겠다. :) 🖊️

C++의 practical 경험이 있다 하더라도, technical interview를 앞두고 이론적인 부분을 한 번 쭉 훑어본 것이 정말 큰 도움이 되었다. 🙌
 

 

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1. Basic Concepts

What is the difference between C++ and C?

OOP

• C: Does not support OOP concepts. Everything is done using functions and structs.
• C++: Supports OOP, allowing the creation of objects, encapsulation, inheritance, and polymorphism.

Standard Template Library (STL)

• C: No built-in data structures like vectors, stacks, or queues. The user has to implement them manually.
• C++: Provides a powerful Standard Template Library (STL), which includes data structures like vectors, lists, sets, and algorithms for searching, sorting, etc.

Memory Management

• C: Memory management is manual, using functions like malloc(), calloc(), realloc(), and free().
• C++: Provides new and delete operators for dynamic memory allocation and deallocation, making it easier and more intuitive to handle memory.

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Explain the concept of pointers and how they work in C++.

Pointers are variables that store the memory address of another variable. They are a fundamental feature in C++ and are used for various tasks like:

• Dynamic memory allocation.
• Passing large structures or classes to functions efficiently.
• Manipulating arrays and data structures.

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What are references in C++? How are they different from pointers?

References are an alternative to pointers for referring to variables. They are often used to:

• Pass arguments to functions to avoid copying.
• Create aliases for variables.

Key Differences:

• Pass by Value: Creates a copy of the object, which can be inefficient for large objects.
• Pass by Reference: Passes a reference (or address) to the original object, which is more efficient and avoids unnecessary copying.
• Const Reference: Allows efficient passing of objects while ensuring that they are not modified.

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Explain the difference between new and malloc.

• malloc:
  • Allocates raw memory.
  • Requires explicit casting and manual error handling.
  • Does not call constructors or destructors.
• new:
  • More powerful and type-safe.
  • Automatically calls constructors and destructors.
  • Throws exceptions on failure instead of returning NULL.

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What are destructors, and why are they used?

Destructors are special member functions in C++ classes that are called when an object of that class is destroyed. They are used to:

• Perform cleanup operations.
• Release resources that the object may have acquired during its lifetime.

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What is a namespace in C++?

A namespace in C++ is used to:

• Group code under a specific name, preventing name conflicts.
• Improve code organization.

Usage:

• Access members of a namespace using the scope resolution operator ::.
• The using keyword can simplify access to elements in a namespace but should be used cautiously to avoid conflicts.

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Python vs C++

• C++: Offers high performance, fine-grained control, and manual memory management, making it suitable for system-level programming and performance-critical applications. It has a complex syntax and requires explicit management of resources.
• Python: Prioritizes ease of use, readability, and rapid development. It features automatic memory management, a rich standard library, and is well-suited for scripting, web development, and data analysis. While its interpreted nature and dynamic typing make it less performant than C++, Python is more flexible and developer-friendly.

 

 

 

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수정이 필요한 내용이나 공유하고 싶은 것이 있다면 언제든 댓글로 남겨주시면 환영입니다 :D