C++ Interview Questions


Q1: What is an abstraction in C++?

Ans: An overview of C++ hides the internal implementations and shows only the necessary details. For example, just writing and clicking on the sending option is utilized when sending an important message through email. This result is the success message shown to indicate that your email has been sent. However, because it does not work for you, the procedure of transferring data by email is not shown.

Q2: What do you mean by call by value and call by reference?

Ans: In the call by value method, we give the functions a copy of the parameter. A new memory is assigned to these duplicated variables, and modifications are not performed in the main function to these values.

Incall by value method, we give to the functions a copy of the parameter. A new memory is assigned to these duplicated variables, and modifications are not performed in the main function to these values.

Q3: Define access specifier and its various types in C++

Ans: An access specifier provides a way of defining how the class members, i.e., functions and variables, can be accessed outside of the scope of the class. In C++ three Access Specifier Types exist:

  • Private - Such class members are not available outside the defined class and only in the same class. Even children's classes can access their parents' lessons.
  • Protected – The children's classes can enter protected members of their parent class in addition to the class in which they are defined.
  • Public - Public access is available throughout the entire program for class members labeled public (code)

Q4: What are the most important differences between C and C++?

Ans:

  • C++ supports references while C doesn’t
  • Functions such as friend features, overloading functions, inheritance, templates, and virtual features are fundamental to C++. The programming language C does not provide these.
  • In C, exception handling in the conventional if-else manner is taken care of. On the other hand, C++ supports language-level exception management.
  • The scanf() and printf() are the most commonly used inputs and outputs in C. In C++, cin is the standard stream for input, and cout is the standard stream for output.
  • C is a language of procedural programming, whereas C++ supports both procedural and object-oriented programming methods.

Q5: Define Encapsulation in C++?

Ans: Encapsulation is the way the data and functions of a class are linked together. It is used for security reasons to restrict the direct access to the data. For this reason, the functions of a class are used. For instance, only the authorized individual may use the customer's net banking facility with the necessary login id and password. This is also solely for his share of the data in the source of the bank.