A Gradual Approach To Learn Object-Oriented Programming

A Gradual Approach To Learn Object-Oriented Programming

Object-oriented Programming or OOP refers to the programming language used by objects. The main focus is on implementation in the programming of real-world entities such as heritage, polymorphism, etc. For example, humans, animals, plants, microorganisms are classified as objects in the class of living things. OOP is used to solve problems in the real world.

OOP has some more advantages including quicker and easier to run, offers a simple program structure that lets others read the code, uses the DRY “Don’t Repeat Yourself” philosophy, making code easy to manage to update and debugging.

A Gradual Approach To Learn Object-Oriented Programming

OOP is also relevant not only in academic exams but also for interviews, in particular Fresher’s interviews. There are several topics in OOP, and we will cover all these topics in the order in this roadmap. If a fresher or student follows this roadmap, he/she is certainly going to split the interview and college or university exams on the basis of OOP programming.

Stage 1 – Fundamentals of Programming

Prior to studying OOP’s Definition, one needs to have basic knowledge of the fundamental concepts and syntax of C++, Java, Python, or any other related language of programming. It will allow you to easily apply the OOP principles in programming.

Stage 2 – What is OOPs & Why it is necessary?

After that, you have to follow OOP’s definition summary points such as:

  • What is programming orientated towards the object?
  • Object-oriented Programming relation with the real world and how it can solve real-world problems?
  • Why should we research object-oriented programming and why do we learn?
  • OOP drawbacks and benefits
  • Difference between Procedural programming and Objective programming?
  • Why is OOP superior to the Procedural Program Language?

So before thoroughly discussing the OOP concepts, you need to know about the above issues. You can follow answers or references to them – For years I have been referring GeeksforGeeks website or any suggested book. The following are the important books for learning OOP:

Stage 3 – Understanding the basics

Following the steps above, we can pass on on the object-oriented programming language pillar as follows:

  • What is Class
  • What is Object
  • Difference between Class and Object.
  • Use of Classes and Object Inside and Outside of Main Class.
  • Can Class and Object exist or use Individually?
  • Real-World Analogy Of Class and Object.
  • Access Modifiers (public, private, protected, etc.)
  • Member Function(Inner and Outer class function)

Stage 4 – Understanding Relevant Keywords:

Important Keywords to learn:

  1. Static Keyword
  2. Virtual Keyword
  3. Abstract Keyword
  4. Final Keyword
  5. Explicit keyword
  6. This Keyword
  7. new Keyword
  8. const keyword
  9. super keyword

You must know these keywords, including their meaning, uses, advantages, and disadvantages and why it is necessary to learn.

Stage 5 – Constructor and Destructor

  • Definition and Working.
  • Rules and Types.
  • Purpose of Using Constructor and Destructor
  • Difference between Constructor and Methods (In Java)
  • Can Constructor Perform Other Task rather than Initialization?
  • Does Constructor Return any value?
  • Constructor vs Destructor.
  • Is there any Constructor Class?

Stage 6 – OOPS features

Polymorphism: one must realize in this:

  • What does polymorphism mean?
  • Categories: Overloading function/operator, Polymorphism compile-time, Overriding function, polymorphism runtime,
  • Which function can be overloaded and which functions cannot be explained overloaded
  • Virtual function
  • Dynamic Binding
  • Virtual Class
  • Derived Class
  • Inline Virtual Function
  • Abstract Class
  • Pure virtual function
  • Pure Virtual Destructor
  • instance of Operator


  • Subclass
  • Superclass
  • Reusability
  • Need for Inheritance
  • Can OOP exist without Inheritance
  • Inheritance types (Single, Multiple, Hierarchical, Multilevel, Hybrid, Virtual Inheritance)
  • Real-life examples of Inheritance
  • Limitation of Inheritance
  • Sealed Modifier
  • Object Slicing


  • Definition
  • Need
  • How to achieve
  • Real-World Example
  • Packages (In Java)


  • Definition
  • When to use
  • How to Achieve
  • Difference between Inheritance and Abstraction
  • Difference between Encapsulation and Abstraction


  • Dynamic Binding
  • Message Passing
  • Object Cloning
  • Wrapper Class

These subjects must also be protected by the essential theory of learning:

  • Get detailed knowledge of the subject.
  • Must know the specifics of implementation.
  • What it has to do with the real world.

Stage 7 – Significant OOP Idea Interview Questions:

  • Important Interview Questions Of OOP Concept:
  • C vs C++ vs Java vs Python (Just get the idea of how they are different)
  • Difference between Procedural and OOP language?
  • Why Java is not a pure Object-Oriented Programming Language?
  • Is an Array a Primitive type or an Object in Java?
  • What are early and late binding?
  • What is the default access modifier?
  • How many instances can be created for an abstract class?
  • Define Garbage Collection and how does it work?
  • Define Manipulators?
  • What do you mean by Final block?
  • What is the final variable?
  • What do you mean by exception?
  • Is an error basically the same as an exception?
  • It is possible for a class to inherit the constructor of its base class?
  • When Should we use Structure instead of Class?
  • Difference and Similar between Struct and class?
  • Scope Resolution operator
  • What is Deep/Shallow Copy?
  • Copy Constructor vs Assignment Operator
  • Can we have more than one value in class?
  • How destructors are different from normal member function?
  • Difference between new and override?
  • Does Overriding Works with Inheritance?
  • Generalization vs Aggregation vs Composition

Important Object-Oriented Designing:

  • Design a HASH map
  • Design LRU cache
  • Design a call Center
  • Design a Deck of Cards
  • Design a parking lot
  • Design an Online Chat System
  • Design an Address Book
  • Design Bank Management System
  • Design an ATM
  • Design Hotel Management System
  • Design Library Management System

A Gradual Approach To Learn Object-Oriented Programming

Rajat Singhhttps://bioinformaticsindia.com
Rajat Singh is the chief Author at Bioinformatics India, he has been writing for the past 3 years and has a special interest in SEO, Technology, Health, Life Sciences and gaming.

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