C++ interview questions

Last update: 18 Feb 2020, 28 QuestionsAsk Question
A Quick Overview of C++
C++ interview questions

Best C++ interview questions And Answers

C++ is the object-oriented programming language.C++ is considered as one of the most esteemed languages to work with when it comes to Operating systems, and games.C++ language is a middle-level programming language designed by Bjarne Stroustrup in the year 1979 in Bell Laboratories. It is an object-oriented language that has features like Inheritance, Polymorphism, Encapsulation, and Abstraction.

It is used to teach the graphics libraries in high-level applications and the applications that are used to communicate with devices over the network.

The latest version of C++ is ISO/IEC 14882:2017 which is also known as C++17. This is the fifth edition.

S.no C Programming Language C++ Programming Language
1. C is a procedural programming language C++ is a procedural and object-oriented programming language
2. The data and functions are different entities C++ data and functions both are encapsulated together into an object
3. Functions cannot be defined inside the structures Functions can be described inside the structures
4. The information cannot remain hidden so that it can be manipulated by another code Encapsulation hides the data thus protecting the data to get used by another code

The benefits of C++ language are:-

  • Faster compared to high-level languages.
  • can be executed on many devices and is easily portable.
  • very good in individual bit changes, so it is perfect for hardware device drivers.
  • great function Library
  • fast and quick language
  • Allows the function overloading.

C++ is called OOPs because it supports Object-oriented Programming which means C++ look into the problem regarding objects rather than the procedure for doing that problem.

OOPS stands for Object-Oriented Programming.OOPS refers to the programming in which programming is based on the objects that can contain data and code rather than based on the functions and procedures.

Features of OOP
  • Object
  • Class
  • Data Hiding and Encapsulation
  • Dynamic Binding
  • Message Passing
  • Inheritance
  • Polymorphism

Class:- Class is the collection of the same type of objects and objects are the variables of the type Class and once the Class has been defined any number of objects can be added to that same class. For examples Eagle, Sparrow, Pigeon, Crow are the objects of the Class Bird

Objects:- Object is the collection of the entities, and the objects occupy the space in the memory. An object contains data and code. When any program is executed the objects interact with each other by sending the messages without knowing their data and code.

The simple meaning of polymorphism is more than one form. In C++ a program can have more than one function with the same name that can perform different activities

Types of polymorphism in C++

  • ad-hoc polymorphism
  • parametric polymorphism
  • subtype polymorphism

In C++ loop is used to perform specific repetitive tasks until a condition is satisfied.


for ( variable initialization; condition; variable update ) {
   // Code to execute while the condition is true

while ( condition )
    // Code to execute while the situation is true

do {
} while ( condition );

Reference variable in C++ is used to give the alternative name to the already defined variable. There is one condition that the reference variable must be initialized at the time of declaration. The reference variables are declared by putting ‘&’ in the constitution

A member function of a class in C++ is a function that has its definition or its prototype within the class like any other variable. Member function operates on an object of the quality of which it is a member, and it has access to all the members of a class for that object.

A member function can be defined inside the class and outside the class.

In C++ every object can access its address through this pointer, in other words, it holds the address of the current object or points to the current object.

S.no Class Structure
1. Members of Class are Private Members of Class are Public
2. Declared as Class Declared as Struct
3. Used for a more significant amount of Data Used for a smaller amount of Data
4. Supports Inheritance Does not support Inheritance
5. The object is created on the Heap memory The objective is formed on the Stack Memory
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