C++ Interview Questions for Freshers and Experienced

Categories: C++

Question:- What are classes and objects in C++?

Answer:- A class is like a blueprint of an object. It is a user-defined data type with data members and member functions and is defined with the keyword class.

You define objects as an instance of a class. Once it creates the object, then it can operate on both data members and member functions.

Question:- What are access modifiers?

Answer:- You use access modifiers to define accessibility for the class members. It defines how to access the members of the class outside the class scope.

There are three types of access modifiers:

1. Private
2. Public
3. Protected

Question:- Difference between equal to (==) and assignment operator(=)?

Answer:- The equal to operator == checks whether two values are equal or not. If equal, then it’s true; otherwise, it will return false.

The assignment operator = allots the value of the right-side expression to the left operand.

Question:- What is the size of the int data type?

Answer:-4 bytes

1. 1 byte
2. 8 bytes
3. 2 bytes
4. 1 - 4 bytes, the integer data type is 4 bytes.

Question:- Which among the following operators cannot be overloaded?

Answer:-

1. -
2. +
3. ?:
4. %

  operator cannot be overloaded because it is not syntactically possible.

Question:- What among these is used to return the number of characters in the string?

Answer:-

1. Size
2. Length
3. Both size and length
4. Name

3. Both size and length are used to return the number of characters in the string.

Question:- Discuss the difference between prefix and postfix?

Answer:-In prefix (++i), first, it increments the value, and then it assigns the value to the expression.

In postfix (i++), it assigns the value to the expression, and then it increments the variable's value. 

Question:- Can you compile a program without the main function?

Answer:- Yes, you can compile a program without the main function, but you cannot run or execute the program because the

 main() function is the entry point, from where all the execution begins. And without the entry point, then you can execute the program.

Question:- What is std in C++?

Answer:-std is a standard class in C++

std is a standard file reading header

std is a standard header file

std is a standard namespace

4 - std is a standard namespace in C++

Question:- What is the C++ OOPs concept?

Answer:-

1. OOPs concept in C++:                                                                               
2. Object
3. Class