These Oops questions have been designed for various interviews, competitive exams and entrance tests. We have covered questions on both basic and advanced concepts which will help you improve your skills to face interview questions on Oops.
Who is this Oops interview questions designed for?
All the developers, programmers and software engineers will find these questions extremely useful. All freshers, BCA, BE, BTech, MCA and college students wanting to make a career in Software Development will be highly benefited by these questions.
Oops interview questions topics
This section covers Oops topics like - Abstraction, Encapsulation, Inheritance, Polymorphism, interface, Class, Object, Constructor, Destructor, Function, Overloading, Early and Late binding etc.
1. What is OOPS?
OOPs stand for Object Oriented Programming System.
It is a technique of programming that focuses on the object.
Object means a real-world entity such as a pen, keyboard, chair, table, computer, Book etc.
Object-Oriented Programming is a methodology or paradigm to design a program using classes and objects.
An Object can be defined as an instance of a class.
Video : OOPS Interview Questions and Answers - For Freshers and Experienced Candidates
2. What are the main principles of OOPS?
It's main principles include -
Abstraction is hiding the complexity of the program that simplifies the program.
Encapsulation is binding the code and data and protecting it from being tampered.
Inheritance refers reusability of the code where new object can inherit the property of parent object.
Polymorphism means having many forms.
3. What is a class?
A class is a template from which objects are created. A class is a blueprint, or prototype which defines and describes the member attributes and member functions.
4. What is an object?
An object is an instance of a class. It has its own state, behavior, and identity.
Software objects are modeled after real-world objects such as a pen, keyboard, chair, table, computer, Book etc.
Just as Real-world objects have its state and behavior; Software objects too have state and behavior.
A software object maintains its state in variables and implements its behavior with methods.
5. What is Encapsulation?
Encapsulation is a principle of wrapping data (variables) and code together as a single unit.
Encapsulation is like your bag in which you can keep your pen, book etc.
Encapsulation means hiding the internal details of an object
Encapsulation is a technique used to protect the information in an object from the other object
6. What is Polymorphism?
The word polymorphism means having many forms. It is the ability of a message to be displayed in more than one form.
Like a man at a same time is a father, a husband, a employee. So, a same person posses different behavior in different situations. This is called polymorphism.
7. What is Inheritance?
Inheritance facilitates reusability and is an important concept of OOPs. Just like a child inherits the traits of his/her parents. With inheritance, we can reuse the fields and methods of the existing class.
8. Define a constructor.
A constructor is a method used to initialize the state of an object, and it gets invoked at the time of object creation.
A constructor is an instance method that usually has the same name as the class, and can be used to set the values of the members of an object
9. Define Destructor.
A destructor is a method which is automatically called when the lifetime of an object ends. The purpose of the destructor is to free the resources that the object may have acquired during its lifetime