Are you an entry-level computer science student looking to learn the basics of C++ programming? If so, you’re in the right place. In this article, we’ll explore some fundamental C++ interview questions tailored to beginners. Whether you’re preparing for an interview or just starting your C++ journey, these questions and explanations will help you build a solid foundation.
1: What are the Different Data Types in C++?
– C++ provides various data types, including primitive, derived, enumeration, and user-defined types. These include int, float, double, char, array, pointer, enum, and user-defined classes.
2: What is the Difference Between C and C++?
– C is a procedural programming language, while C++ is an object-oriented programming language.
– C++ supports data hiding through encapsulation, whereas C does not.
– C++ is a superset of C, meaning that C++ includes all of C’s features and adds more, such as classes and objects.
3: What are Classes and Objects in C++?
– In C++, a class is a user-defined data type that contains data members and member functions.
– An object is an instance of a class, allowing you to work with the data and methods defined in that class.
4: What is the Difference Between Struct and Class?
– In C++, a structure (struct) is similar to a class, but members are public by default.
– A class has private members by default, which provides better encapsulation.
5: What is Operator Overloading in C++?
– Operator overloading allows you to redefine the behavior of operators like +, -, *, /, etc. for user-defined data types.
– For example, you can overload the ‘+’ operator to add two complex numbers.
6:- What is Polymorphism in C++?
– Polymorphism means having many forms. It allows different behaviors in different situations.
– C++ supports both compile-time and runtime polymorphism through function overloading and virtual functions.
7: Explain Constructors in C++.
– Constructors are special member functions that are automatically called when an object is created.
– Constructors have the same name as the class and initialize object attributes.
8: Tell Me About Virtual Functions.
– A virtual function is a member function in the base class that you can override in a derived class.
– It is declared using the `virtual` keyword and enables dynamic binding.
9: Compare Compile-Time and Runtime Polymorphism.
– Compile-time polymorphism is resolved at compile time through function overloading.
– Runtime polymorphism is determined at runtime using virtual functions and pointers.
10: What is a Friend Class and Friend Function in C++?
– A friend class can access private, protected, and public members of other classes where it’s declared as a friend.
– A friend function can access these members and is not a member function of the class.
11: What are the C++ Access Specifiers?
– C++ has three access specifiers: public, protected, and private.
– Public members are accessible from outside the class, protected members within the class and derived classes, and private members only within the class.
12: Define Inline Function.
– An inline function is a function where the compiler places a copy of the code at each function call site.
– It’s used to eliminate the function calling overhead for better performance.
13: What is a Reference in C++?
– A reference is another name for an existing variable. Once initialized, it can be used interchangeably with the variable name.
– Changes to a reference are reflected in the original variable.
14: Explain Abstraction in C++.
– Abstraction is the concept of showing only essential details to the user while hiding irrelevant or internal information.
– Classes and objects provide a way to implement abstraction in C++.
15: Is Destructor Overloading Possible? If Yes, Explain Why. If No, Explain Why Not.
– Destructor overloading is not possible in C++. Destructors take no arguments, and there’s only one way to destroy an object.
16: What is Call by Value and Call by Reference?
– Call by value involves passing a copy of the parameter to the function, and changes do not affect the original variable.
– Call by reference passes the address of the variable, allowing changes to affect the original variable.
17: What is an Abstract Class, and When is It Used?
– An abstract class cannot have instances and serves as a base for derived classes.
– Abstract classes often contain pure virtual functions and are used for creating a common interface for derived classes.
18: What Are Destructors in C++?
– A destructor is a special member function that is automatically called when an object is destroyed.
– It is used to clean up resources associated with the object.
19: What Are Static Members and Static Member Functions?
– Static members belong to the class, not to instances of the class. They are shared among all objects.
– Static member functions can be called using the class name and do not operate on instance-specific data.
20: Explain Inheritance.
– Inheritance allows you to create new classes (derived) from existing classes (base).
– Derived classes inherit the attributes and methods of the base class, promoting code reuse.
These C++ interview questions are a great starting point for entry-level computer science students looking to grasp the basics of C++. Understanding these concepts will not only help you succeed in interviews but also lay the foundation for your C++ programming journey. As you progress, consider exploring more advanced topics and real-world applications to deepen your knowledge. Happy coding!