C++ Interview Questions and Answers

C++ basics Interview Questions and Answers. C++ is an Object-Oriented programming language. It is a superset of C language and also called as extended version of C programming language. In this article, you will learn some of the most common C++ Interview questions and answers.

1. What is C++ Programming Language?

It is an object-oriented programming language developed in 1985. Bjarne Stroustrup created it. Basically, C++ is an updated version of C with classes and objects.


The object-based programming language allows users to create applications using objects and classes. The concept of object-based programming is similar to that of object-oriented programming, but it has inheritance as an added benefit. There are many object-based programming languages, such as JavaScript, Python, and Ruby.


The purpose of an object-oriented language is to create models that are based on the real world by using objects and classes. Object-oriented programming (OOP) languages are designed to overcome the drawbacks of procedural programming languages by allowing developers to create objects that can hold both data and behavior. Examples of object-oriented languages include Java, C++, Python, and Ruby.


Smalltalk, Java, etc.


These are some of the advantages of the C++ language:

  • Due to its cross-platform capability, it is a portable language.
  • It is an object-oriented programming language that includes classes and objects.
  • Rich function libraries are available.
  • As it supports polymorphism, inheritance, and friend functions, it is a powerful tool for designing applications.
  • The data hiding feature of C++ ensures the security of data.

A variable is a name of memory location.


Constants are data items whose values cannot be changed.


A character constant is a constant that contains a single character enclosed within a single quote.


A keyword in C++ is a predefined word. The meaning of keywords cannot change. So, they are called reserve words.


Tokens are the smallest individual units in programs.


It is a block of code that can be accessed anywhere within the system and that serves a specific purpose.


Variables should be declared as soon as they are needed. In other words, whenever a program needs to use a variable, it should be declared before it is used.


A function prototype is the skeleton of a function.


A function gets called when the function name is followed by a semicolon.


Defining a function involves the use of braces with one or more statements within.


A programming language uses control statements to cause the flow of execution to advance and branch based on changes to the state of a program. Control statements in C++ programs fall into three categories: selection, iteration, and jump.


By using selection statements, the program can determine which path to follow based on the outcome of an expression or the state of a variable.


The iteration statement allows a program to repeat one or more statements. For, while, and do-while are the three iteration statements in C++.


Programs can execute in a nonlinear manner using jump statements.


The collection of similar data types stored in a contiguous memory location is known as an array.


An object is any physical thing that exists in the real world.


A C++ class is a collection of functions and data with a single name. This is a blueprint for an object. Classes are one of the most important parts of a C++ program. C++ programs can have any number of classes.


The concept of a structure refers to a collection of dissimilar data types.


In a class, the data members are private by default, while in a structure, they are public by default.


The insertion operator (<<) is a member operator of the ostream object and is used for writing to the output device.


The extraction operator (>>) is a member operator of the istream object and is used for writing to your program’s variable.


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