Wednesday, 24 April 2013

OOPS Concept With Real Life Example

OOPS Concept With Real Life Example

This is the most asked Question in a technical interview in any domain.. OOPs Concept is very very important.. Today I will explain OOPs concept with real Life Example that will help you to grasp the concept well and excel in the interviews...

Objects: Object is the basic unit of object-oriented programming.Objects are identified by its unique name. An objectrepresents a particular instance of a class. There can be more than one instance of an object. Each instance of an object can hold its own relevant data.

An Object is a collection of data members and associated member functions also known as methods.

Classes: Classes are data types based on which objects are created.Objects with similar properties and methods are grouped together to form a Class. Thus a Class represent a set of individual objects. Characteristics of an object are represented in a class as Properties. The actions that can be performed by objects becomes functions of the class and is referred to as Methods.

Example #1:

For example consider we have a Class of Cars under which Santro Xing, Alto and WaganR represents individual Objects.In this context each Car Object will have its own, Model,Year of Manufacture, Colour, Top Speed, Engine Power etc.,which form Properties of the Car class and the associated actions i.e., object functions like Start, Move, Stop form the Methods of Car Class.No memory is allocated when a class is created. Memory is
allocated only when an object is created, i.e., when an instance of a class is created.

Example #2:

An architect will have the blueprints for a house....those blueprints will be plans that explain exactly what properties the house will have and how they are all layed out.  However it is just the blueprint, you can't live in it.  Builders will look at the blueprints and use those blueprints to make a physical house.  They can use the same blueprint to make as many houses as they want....each house will have the same layout and properties.  Each house can accommodate it's own one house might have the Smiths live in it, one house might have the Jones live in it.

The blueprint is the class...the house is the object.  The people living in the house are data stored in the object's properties.

Abstraction: Abstraction means showing essential features and hiding non-essential features to the user.

For Eg.  Yahoo Mail...

When you provide the user name and password and click on submit button..It will show Compose,Inbox,Outbox, and so when you click on compose it will open...but user doesn't
know what are the actions performed internally....It just Opens....that is essential; User doesn't know internal actions ...that is non-essential things...

For Eg. Tv Remote..
Remote is a interface between user and tv..right. which has buttons like 0 to 10 ,on /of etc but we dont know circuits inside remote...User does not  need to know..Just he is using essential thing that is remote.

Encapsulation: Encapsulation means which binds the data and code (or) writing operations and methods in single unit (class).
For Example:
A car is having multiple steering,wheels,engine...etc..which binds together to form a single object that is car. So, Here multiple parts of cars encapsulates itself together to form a single object that is Car.

In real time we are using Encapsulation for security purpose...

Encapsulation = Abstraction + Data Hiding.

Inheritance: Deriving a new class from the existing class,is called Inheritance.
Derived(sub class) class is getting all the features from Existing (super class\base class) class and also incorporating some new features to the sub class.

For Eg.,

class Address
String name;
String Street name;
class LatestAddress extends Address
String City;
String State;
String Country;
public class Vishal
LatestAddress la = new LatestAddress();
//Assign variable accordingly...

In the above Example class LatestAddress getting all features from the Address class.
In the LatestAddress class we have total 6 properties..3 are inherited from Address class and 3 properties are
incorporated. So In the class Vishal we are declaring the object of class LatestAddress and then assign new variables using the properties of the previous base classes... So this is a nice example of inheritance..

Polymorphism :

Polymorphism means ability to take more than one form that an operation can exhibit different behavior at different instance depend upon the data passed in the operation.

1>We behave differently in front of elders, and friends. A single person is behaving differently at different time.

2> A software engineer can perform different task at different instance of time depending on the task assigned  to him .He can done coding , testing , analysis and designing depending on the task assign and the requirement.

3> Consider the stadium of common wealth games. Single stadium but it perform multiple task like swimming, lawn tennis etc.

4> If a girl is married and mother of 2 children doing teaching job then  she is a women first ,, teacher in a school when she is in school,,wife of someone at home,, mother of her children,, and obvious daughter of someone & may be girl friend of someone (just kidding) means a woman plays diffent roles at different times dats the polymorphism (many forms).


OOPs have following features:

1. Object             - Instance of Class
2. Class               - Blue print of Object
3. Encapsulation    - Protecting our Data
4. Polymorphism   - Different behaviors at different instances
5. Abstraction        - Hiding our irrelevant Data
6. Inheritence        - One property of object is acquiring to another property of object


  1. good examples...
    very useful for beginners....

  2. good and it is easy to learn and understand

  3. Nice job vishal:)
    keep going on!!!

  4. very clear example i have ever seen before...

  5. Good example and good pratices

  6. Very very clear oops concept.......thanks u very much sir.

  7. really very good examples................
    interesting + understanding

  8. Good Explanation and Very clear.
    Thanks a lot.

  9. nice examples particular girl example nice..

    total explanation very clear and awesome

  10. thanks for the simple and clear explanation

  11. Very good explanation...!!! Keep posting...!!!

  12. very nice examples

  13. Thnx is really helpful....

  14. All the concepts are well explained....good job!

  15. very good examples .. Nice post ..

  16. Nice examples to understanding...thank you

  17. Mr Kartikeyan asked the following Question:


    "I read your article about oops concept that is really nice sir.

    I have one doubt sir that is mentioned below plz clear as soon as possible

    class - " The blueprint of house "

    object - " The physical houses which was build using house blueprint"

    attributes - " The people who living in the house are data of the object properties"

    methods - " methods ?"

    Give me one example which comprises of above all?"


    The answer to Mr Kartikeyan's Question is as follows:

    "Methods are action which an object is able to perform.. For example in the above example.. The people living the house are able to perform certain actions like repair their house, Paint it. So the actions like repairing and Painting are all methods for the objects."

  18. thank you,its very useful and easy to understand.i need the concept of function overloading/overriding with real time example.....

  19. Nice one. Beautifully exampled.Thanks. Keep it going.

  20. now oops concepts seems to be vry simple to understand nd learn..

  21. very interesting to learn and good examples keep on posting such easy ways to learn basics thanq very much

  22. Good Explainaotion of OOPS Concepts

  23. OOPS concepts are explained in such a way that beginners can easily understand and remember

  24. thanks!!!!! really helpful :) :)

  25. really nice examples......easy to understand....

  26. Thank you...its a very clear and nice explanation

  27. Thanku sir,i understand very clearly.

  28. Thanku sir,i understand well with your explanation.

  29. Easy to understand. very good

  30. thanx a billian ....gr8 examples

  31. Good Examples..Thanks for sharing..its realy helpful for me..

  32. Miss Sangeeta Korade asked the following Question:

    "Explain the four major pillars of oops taking keyboard as an example?"

    Answer to her Question:

    The Four major Pillars of OOPs are:

    1. Abstraction
    2. Encapsulation
    3. Inheritance
    4. Polymorphism


    For Example, In a keyboard, we have circuits and It is connected to the CPU. So While pressing the key we dont know about the inside happenings of the keyboard. We only know that When the keyboard is pressed It will display a similar letter in the screen incase we are typing. So this is how Abstraction works. Abstraction ie., Exposing necessary data


    Next When the key is pressed some kind of message runs through the circuit of the keyboard which is sent to the CPU.CPU analyses that request and accordingly displays the pressed text in the screen. So here we only know that pressing the key will display the letter but In the meanwhile we are totally unaware of the happening inside the circuits. This is Encapsulation ie.,emphasis on hiding the data


    There are many keyboards brands available in the market but the similarity between them is that they follow more or less the same prototype as the Keyboard available in the year 2000. So basically they are inheriting the properties of the older generation of keyboards plus they are modifying the newer keyboards with some extra functionalities..


    Polymorphism means Poly[Many] + Morphism[Forms]. It is the ability of the object to behave differently under different situation.. For Example while writing a word document you will be using the up/down arrows for moving up and down in the document but while playing a car game u will be using the same keys for moving your car in the game. So the same keys are behaving differently on various scenarios and this is called polymorphism.

    1. awesome reply sir. you must be the "father of examples" in computer world..thanks again for such a great explanation.

  33. its really superb. tanx for ur post vishal

  34. thank yo seasy to understand

  35. Very good explanation with Simple Examples..!!
    Keep posting...!!!

  36. nice defination and real life example

  37. Very easy to understand.. great job Vishal. Thank you so much..

  38. really very easy defnition and good examples

  39. explanation is too gud. I'm a beginner so this examples of oops helps me alot...


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