C++ is still as relevant today as it was during its advent in the mid-80s. The imperative, object-oriented programming language is widely used as a general-purpose programming language. As such, several jobs require candidates to have a profound understanding of C++.
We’ve put together a list of the most important C++ interview questions and answers to help you prepare for an interview. We’ve divided the questions into basic, intermediate, and advanced.
C++ Interview Questions And Answers | C++ Interview Questions And Answers For Freshers | Simplilearn
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C++ is a powerful and all-purpose programming tool developed by Bjarne Stroustrup at Bell Labs. This language is an extension of C and is by far one of the fastest object-oriented programming languages. C++ is super popular because of its high speed and compatibility.
It is widely used in the development of games and servers while some of the real-world applications of C++ are as follows
So, today, well understand the different C++ questions asked in an interview at a basic, intermediate and advanced level. Crack your next tech interview with confidence! Take a free mock interview, get instant⚡️ feedback and recommendation
C++ Interview Questions For Freshers
The 4 data types in C++ are given below:
Intermediate Level Interview Questions
vTable is a table containing function pointers. Every class has a vTable. vptr is a pointer to vTable. Each object has a vptr. In order to maintain and use vptr and vTable, the C++ compiler adds additional code at two places:
- Of the object being created
- To point to vTable of the class
Function overloading allows two or more functions with different types and number of parameters to have the same name. On the other hand, operator overloading allows for redefining the way an operator works for user-defined types.
Yes, it is possible. However, as the main() function is essential for the execution of the program, the program will stop after compiling and will not execute.
A destructor is the member function of the class. It has the same name as the class name and is also prefixed with a tilde symbol. It can be executed automatically whenever an object loses its scope. A destructor cannot be overloaded, and it has the only form without the parameters.
The compiler provides a constructor to every class in case the provider does not offer the same. This is when the programmer provides the constructor with no specific parameters – this is called a default constructor. The code for default constructor can be displayed in the following example.
No, we cannot provide one default constructor for our class. When a variable in the class type is set to null, it means that it was never initialized and the outcomes will be zero.
The keyword struct is used for resembling public members by default, while the keyword class is used for resembling private members by default.
The program will ask the user to enter 5 numbers and then present with their sum. For instance,
Enter 5 numbers: 22
Any function when accompanying the virtual keyword exhibits the behavior of a virtual function. Unlike normal functions that are called in accordance with the type of pointer or reference used, virtual functions are called as per the type of the object pointed or referred.
In simple terms, virtual functions resolve at runtime, not anytime sooner. Use of virtual functions could also be understood as writing a C++ program leveraging the concept of runtime polymorphism. Things essential to writing a virtual function in C++ are:
An example demonstrating the use of virtual functions (or runtime polymorphism at play) is:
In the aforementioned program bp is a pointer of type Base. A call to bp->show() calls show() function of the Derived class. This is because bp points to an object of the Derived class.
There are two important distinctions between a class and a structure in C++. These are:
Denoted by the static keyword, a static member is allocated storage, in the static storage area, only once during the program lifetime. Some important facts pertaining to the static members are:
The reference variable in C++ is the name given to the existing variables. The variable name and reference variable point share the same memory location in C++, which helps in updating the original variable using the reference variable. The code can be displayed in the following example.
What is the difference between C and C++?
The main difference between C and C++ are provided in the table below:
| C | C++ |
|---|---|
| C is a procedure-oriented programming language. | C++ is an object-oriented programming language. |
| C does not support data hiding. | Data is hidden by encapsulation to ensure that data structures and operators are used as intended. |
| C is a subset of C++ | C++ is a superset of C. |
| Function and operator overloading are not supported in C | Function and operator overloading is supported in C++ |
| Namespace features are not present in C | Namespace is used by C++, which avoids name collisions. |
| Functions can not be defined inside structures. | Functions can be defined inside structures. |
| calloc() and malloc() functions are used for memory allocation and free() function is used for memory deallocation. | new operator is used for memory allocation and deletes operator is used for memory deallocation. |
FAQ
What are good C++ interview questions?
- What is the difference between C and C++? …
- What are classes and objects in C++? …
- What are access modifiers? …
- Difference between equal to (==) and assignment operator(=)? …
- What is the difference between a while loop and a do-while loop? …
- What is the size of the int data type?
What is C and C++ interview questions?
Can I use C++ for interview?
What is the difference between C and C++ interview questions?
