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C++ Interview Questions

Last Updated: Nov 10, 2023

Table Of Contents

C++ Interview Questions For Freshers

What is the difference between logical AND (&&) and bitwise AND (&) operators?

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What are the basic data types in C++?

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What is a pointer in C++?

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Explain the concept of operator overloading in C++.

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Operator overloading in C++ is a feature that allows programmers to redefine the behavior of certain operators when they are used with user-defined types. This means that operators such as +, -, *, /, and many others can be given new meanings and behaviors beyond their predefined operations with built-in types. This ability to extend the functionality of operators is a powerful feature of C++ that enables the creation of more intuitive and expressive code.

Operator overloading involves creating special member functions or global functions with the same name as the operator, followed by the keyword "operator" and the symbol of the operator to be overloaded. These functions take one or more user-defined type arguments and return a value of the desired type.

For example, consider a class called Vector that represents a mathematical vector. By overloading the + operator, we can define a way to add two Vector objects together:

class Vector {
    float x, y;

public:
    Vector(float x, float y) : x(x), y(y) {}

    Vector operator+(const Vector& other) const {
        return Vector(x + other.x, y + other.y);
    }
};

Now, we can use the + operator to add two Vector instances:

Vector v1(2.5, 3.7);
Vector v2(1.9, 4.2);
Vector sum = v1 + v2;     // Calls the overloaded operator+
  • Benefits of operator overloading:
  • It allows us to write more natural and intuitive code by enabling the use of operators with user-defined types.
  • It promotes code reusability and improves the readability of the code by providing familiar syntax for performing operations.
  • It can simplify complex mathematical or logical operations by encapsulating them within operator overloads.
  • It allows the creation of domain-specific languages by defining operators that mimic the syntax of those languages.

However, it is important to use operator overloading judiciously to avoid confusion or ambiguity in code. It is recommended to follow established conventions and provide intuitive semantics when overloading operators to ensure the maintainability and understandability of the code.

What is the difference between pass by value and pass by reference?

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What is a constructor in C++?

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What is the difference between a class and an object?

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Explain the concept of inheritance in C++.

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What is dynamic memory allocation in C++?

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What is the difference between composition and inheritance?

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Explain the concept of virtual functions in C++.

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What is polymorphism in C++?

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What is a destructor in C++?

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What is the size of an integer data type in C++?

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What is the difference between a compiler and an interpreter?

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What is a namespace in C++?

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What is function overloading in C++?

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What is the difference between public, private, and protected access specifiers?

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What is a template in C++?

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C++ Intermediate Interview Questions

What is a template specialization in C++?

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What are the storage classes in C++?

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Explain the concept of namespaces in C++.

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What is the difference between a shallow copy and a deep copy?

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What is an abstract class in C++?

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What is function overriding in C++?

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What is operator precedence in C++?

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What are the differences between struct and class in C++?

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What is a copy constructor in C++?

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Explain the concept of templates with an example.

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What is multiple inheritance in C++?

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What is a static member variable in C++?

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Explain the concept of exception handling in C++.

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What is the difference between function overriding and function overloading?

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What are the advantages of using references instead of pointers in C++?

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Using references instead of pointers in C++ has several advantages: 1. Null safety: References cannot be null, eliminating the possibility of crashes due to null pointers. 2. Simplicity: References are simpler to use and require less syntax than pointers. 3. Automatic dereferencing: References automatically deference, making the code more readable and concise. 4. No memory management: References do not require manual memory management like pointers, reducing the risk of memory leaks. 5. Functionality with operator overloading: References can be used with operator overloading, allowing for more expressive and intuitive code.

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What is the scope resolution operator (::) used for in C++?

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What is a friend function in C++?

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What is a virtual destructor in C++?

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A virtual destructor in C++ is used to ensure proper destruction of objects in an inheritance hierarchy. When a base class pointer is deleted, the virtual destructor of the derived class is called, allowing for the appropriate cleanup of resources allocated in the derived class.

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What is the difference between new and malloc?

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What is a pure virtual function in C++?

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C++ Interview Questions For Experienced

What is a smart pointer in C++?

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What is an object-oriented programming language?

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Explain the concept of function templates in C++.

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What is multiple inheritance and what are its advantages/disadvantages?

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Explain the concept of operator overloading with an example.

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What is a lambda function in C++?

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What is the role of virtual functions in polymorphism?

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What is the use of const keyword in C++?

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What are the differences between the new and delete operators and the malloc and free functions?

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Explain the concept of function pointers in C++.

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What is the diamond problem in multiple inheritance and how can it be resolved?

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What is the difference between early and late binding in C++?

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Early binding, also known as static binding or compile-time binding, refers to the process of linking a method or function call to its definition during the compilation phase. Late binding, also known as dynamic binding or runtime binding, refers to the process of linking a method or function call to its definition during the execution phase. The main difference is that early binding is resolved at compile-time, while late binding is resolved at runtime.

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What is the use of RTTI (Run-Time Type Information) in C++?

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Explain the concept of an abstract base class in C++.

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What are the differences between static and dynamic polymorphism?

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What is the role of the const qualifier in function parameter types?

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What is the difference between a pure virtual function and a virtual function in C++?

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In C++, a pure virtual function is a virtual function that is declared but has no implementation in the base class. It is used to create an abstract class, which cannot be instantiated directly. On the other hand, a virtual function is a function that can be overridden in derived classes and has a default implementation in the base class. It allows for runtime polymorphism.

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