Association, Aggregation, Composition, Abstraction, Generalization, Realization, Dependency

Thank you..
Looking forward for your next post…

very nice content to start

Thanks!

Now these basic can be easily differentiated, after read this post

Very helpful. Thanks.

Nice article. Explanation the concepts clearly.Thank you

Good article. Thanks.

Very nice and easy to understand in a simple definitions.

It will be still good iy you give examples with code also.

thanks for posting.please update Java with ibatis configuration it is helpful to us
thanks in advance

An example for aggregation is missing and it could be like:

A car has a stereo system.A car can exist without a stereo system. There exists aggregation between car and stereo.

Really very good and straight forward description about the Association, Aggregation, Composition, Abstraction, Generalization, Realization, Dependency. Thank you so much..

Its very handy too..

Cheers,
Prashant.

Superb Example.

Keep Posting Joe

Thanks! Very nice explanation.

Thanks for helping……………

Good explain…

Hi ,

thnaks for that information.

but i think i havnet understand that last.(Dependency)
does it comes with arrow or just —- lines. pls post me

Great Post! It clear my mind.

Really Good article. Nice work.

nice… its in a generalized way….very helpful

Sir. i m n trouble..if u post full code .which contain aggregation and compostion.then it will be very clear to all of us.according to programing point of view.
and realy good work u have done.we appriciate ur work…
plz post full code waiting 4 ur reply

very nice article… it clearly explains the basic concepts… thanx!

Thanks Joe for the wonderful post. It is really quite useful.Most of the times we tend to get confused with these terms as all sound the same. Few more additions would make it better:
a) Class diagrams
b) Code for Aggregation and Composition

Thank You Very Much… It Was Very Helpfull…

Thank you for addressing all relevant items.. little bit more code would be marvelous. still great. CDW

Good explaination mate

Terse explanation of Association, Aggregation and Composition..!!! :) Thanks a lot… :)

Looking forward for your next posts…

i searched most of the definitions for these association,aggregation and composition…u cleared my doubt …u people are explaining like baby feeding thank you……

jst superb…think u r bst faculty for starters..i bliv in it…”with strong foundationz u can aim for the sky.”

Hi,

The definition given in this site is very clean and neat and simple and very understandable instead of blah..blah…

Cheers !!!
KM

thank you very much for sharing your knowledge. very useful content. I learnt the concept very well to be applied in OOAD.

I was always get confused for these relationship but as you defined these relationship it became easy to understand. Thanks buddy :)

Thanks for these information. Great definition for aggregation n composition

Very nice page.
It contains all required information about association, aggregation, composition.
thanks a lot.
Prabhat.

Nice.. Thank You..

Hi,

good article.

Thank you.

hi,
thanks for info.this is nice with example.this is really helpful for student as well as employee.
22/jan/2011

very clear and crisp.

it’s so clear so far what I see!
thank you!

Easy to understand.Nice Post.

Very nice….

Thanks ,
your definition is very clear

Sir,
please describe me multiple inheritance,candidate key, in oops.

Sir,
Please let me know how to depict association, aggregation and composition in java code.

Regards,
Shylaja V.

thanks this artical is very easy to understand

please give some examples of programs as illustration for class relation……
it will be useful.
and thanks very much for this nice post.

Hey,

Its sweet & simple !! You made task very simple and anyone can understand.

Great Work!!!!

it is simple and very easy to understand
thank you,

simple and understanble…
Thanks a lot

Great Work !!!
Keep going on !!!

All the best !!

Very nice article. I am facing a unique situation where we have modeled a test case with two compositions between the same two entities. Is this realistic? If so, can you give me a real world example for this?

thank you for you very clear work joe.

Wow., Awesome work., Thankz,
Keep up the Good work.,

thanks much. very useful information

thankz sir , very nice content

thanks sir,

this content is very helpful and outstanding

thanks for give simple & informational content

thanks 4 this outstanding content

mast laga maja aagaya…………

Excellent! Thanks so much.

its very useful for my net i need more info about ooad

Nice article. Keep going.

very nice

very Nice article……
but need some coded exemples……

BTW thank you very much.

very nice understanding…thanks

Excellent, keep it up. Can you explain some of the fewdesign patterns in better understandable way.

Thanks a lot buddy.

Girish

could you please provide some code samples for association, aggregation and other all oops concepts.

Thanks
Varma

multiplicity is no given here :) pls add

thanks

Its a great post. Thanks Man!

Please give me a simple explanation with example on difference between abstraction and encapsulation.

Very nice post…

hi,
very nice approach i realy like this complete definition pakage with examples

Really nice explanation . Simple and easy to understand
I liked the formate of your blog….the best i seen till now

Nice

K eep
I t
S imple
S illy

Completely Followed

Nice Simple Sober & Easily Grab-able & Understandable

nice, short, simple and good explanatory.

Nice one
Thanks

Sir……this is the best notes of Association I ever seen…….thanks a lot for the simple ans besr definations…

Simply Superb

very nice

Very easily explained and easy to understand all the definition. Keep it up

too much informative

simply super….very useful Thanks for posting..

This article is very helpful and well explained. Thanks

Good Artcile. it helps.. Thanks..!

very nice sir. . . . thank u vry much………

it helped me alot sir………thank u sir

Very good post, easy way of understanding thank u

Useful information with good explanation well done Joseph..

realy good article

Thanks dude.. its really so simple to understand these stuffs…….. really gr8 work.

nice explanation.. thiru

Very Good article… Thank you..

thanks for simple explanation of association, aggregation, composition. Good Work…Thank you..

it is so easy and interesting

explanation also easy for preparing answerssssssssssss

Nice Article Joe..Like very much the way you describe ,Must say Very good Article for the beginners …!!!

Superb Article !!!!!!!!!

Nice Article, Much useful for a beginner

very good explanation on composition and aggregation relationships

Dear sir, I need more explanation and example about abstraction… How to apply in c…? i use data structure linked list concept..

Aggregation
———————-
Aggregation is a relationship between two classes that is best described as a “has-a” and “whole/part” relationship. It is a more specialized version of the association relationship. The aggregate class contains a reference to another class and is said to have ownership of that class. Each class referenced is considered to be part-of the aggregate class

Ownership occurs because there can be no cyclic references in an aggregation relationship. If Class A contains a reference to Class B and Class B contains a reference to Class A then no clear ownership can be determined and the relationship is simply one of association.

For example, imagine a Student class that stores information about individual students at a school. Now let’s say there is a Subject class that holds the details about a particular subject (e.g., history, geography). If the Student class is defined to contain a Subject object then it can be said that the Student object has-a Subject object. The Subject object also makes up part-of the Student object, after all there is no student without a subject to study. The Student object is therefore the owner of the Subject object.
Examples:

There is an aggregation relationship between Student class and the Subject class:

public class Subject {

private String name;

public void setName(String name)
{
this.name = name;
}

public String getName()
{
return name;
}
}

public class Student {

private Subject[] studyAreas = new Subject[10];

//the rest of the Student class
}

Nice one.

This website is very useful . but i need short notes and examples for full oops concepts in c++.

material is good but it explain with diagram then it is more effective for readers

Nice explanation. It would recommend to add few more real world examples that could help to understand it more easily.

Nice explanation on the topics of association, aggregation and composition with quite undrestandable language.

Excellent, A quick glance with best understanding. Keep it up

very helpful and easy 2 understand
Thank you

You mentioned in this article – Abstraction is specifying the framework and hiding the implementation level information. Abstraction never says about hiding anything. Let’s take an Example of Employee with Super class and Manager and Salesman bening subclass of Employee. So if Employee may provide various implentation in common, but can’t have implementation for calculateBonus because this is fully dependet on nature of employee subclass, and hence Employee would have calculateBonus as abstract. So overall, abstraction is isolation of common essentioal behaviour and supress unimportant behaviours. Abstraction never meanse hiding anything. Hiding of implementation from accidental access is Encapsulation.

Thanks
Arun Deo

This is very nice explanation with the examples. It helps to crystal clear the things, that have very confusing boundary among them.

Its really nice.I was always get confused for these relationship association, aggregation and composition.Thanks a lot

its really nice. keep going its really helps lot,

Thanks,
Prabhu.

Wonderful… Very nice simple & easy to understood details which might be very complex for beginner……

Appreciate your effort….

Nice Article on relationships

really it’s a nice content that you provide through this web. It removes all of my confusion.
thanks

Sir, i want to briefly explanation of attributes……..

thank u soo much, nice explanation , i really want this :)

Very nice post.. i have never experienced such
simple examples for explaining such complex terms like aggregation and composition
i thought so far.. Keep posting…

Best article on association aggregation composition

Thanks…

Hi, may I seek a clarification about generalization concept. Let’s say I have a two kinds of staff, Manager and Supervisor and both have the same attributes (name,contact number). So, is it possible to say that this has a generalization relationship – Staff as the superclass, Manager and Supervisor as its subclasses althought there’s no difference in terms of the attributes between Manager and Supervisor?

Thanks you very much for share good knowledge for me .

A very good explanation..I never seen before like this type explanation about this concept

very nice artical!!

Very nice explanation about class diagram terms…

Questions
1. Identify and briefly explain the objectives, classes, method and attributes for a hotel reservation system.
2. Draw a use case diagram to represent a hotel reservation system.
3. Draw a class diagram that models hotel reservation system data structure, clearly representing the objects, classes, associations, generalization and aggregations.

Thanks

Questions
1. Identify and briefly explain the objectives, classes, method and attributes for a hotel reservation system.
2. Draw a use cases diagram to represent a hotel reservation system.
3. Draw a class diagram that models hotel reservation system data structure, clearly representing the objects, classes, associations, generalization and aggregations.

Thanks

Really simple and excellent explanation. Easy to understand for beginners…!!!

Very good explanation

Superb Explanation…Keep It Up!

dddddddd

thanks friend

identify in detail association and aggregation

Nice one
thank you

Gud NOtes

crystal clear dude.

Thanks..!! M sure your examples gonna help in tomorrows exam.

A book CAN exist without a library…. Incorrectly quoted…… Rather a library CANNOT exist without a book….

Very nice narration.

Write an example program each showing dependency,
generalisation relationships in JAVA

Thanks for the useful info

Nice explanation. If you would provide with one example all the above along with diagams that would be excellent.

Good article. One of the questions mentioned above, was related to manager,supervisor and staff. Certainly there is a generalization relationship with Staff as superclass and manager and supervisor classes are subclasses inheriting from Staff. Though attributes could be same in manager and supervisor when it comes behaviour(methods) manager and supervisor classes are specialized with inheriting the generic class i.e., Staff.

Lun smjhaya h tounae

Thank’s man for this article, i found it very helpful for me. Am studying SCJA and i was looking for any comprehensive material for UML basics like this one.

its nice. very simple defnation. easy to understand.

Awesome post!!!Keep it up.

Nice article on UML concepts. The content of the article is very simple to understand. Thanks.

Brother your website have beautiful GUI. Keep it up, and keep it UP.

Nice Post, Hope to get same clarity on design patterns.

Thank you.

very nice…nd thanx..

NUMBER # 1
Very Clear Topic About the English WORDS “Aggrega…composi…reali…generai….etc etc…etc”

But how can i understand when i want to implement your dictionary details (read NUMBER # 1) on practicing programming ???
specially JAVA…

Awesome notes.

Really helpful

Awesome…….really good way to understand newcomers!!

Simple & Clear Explanation for the beginners.

Thanks!!

this is simple way to understand any definition

Awesome…….really good way to understand newcomers!!

Thank you.

easy way to understaing.
thanks….

Clean & clear explanation. Thanks Joe.

really nice

Simplysuperb, lots of information with very simple words.

Wonderful Job Joe. Keep it up.

really clears the confusion.

Nice way of information.
Thanks………………

Hi,

Superb Explanation sir .

Really good man easy to understand

really helping me a lot….
u r dng a great work.Thank You

is it nice…

i have got some idea…

thanks ..

you have to increase the paragraph

very nice explanation.

neat and clear description dude…

Hi.. Useful explanation and easy to understand. thankyou

This is good post. thanks a lot

Its really post .

Vidhi Jain

Very nice…Thanks

best for beginner….like me
thank you sir

explained in very effective n simple way

explained in very effective n simple way, doing a great job

please change the background color, so that it would be more readable

Thank you very much sir. It is ow-some….

Good to start for beginners and experienced juggling between these concepts.

Thanks a lot , good explanation with easy example ..

Thanks :Great people explain concept in the simple and easy understandable way.

Madappa.i

that was a very good explanation. simple and easily understandable…

thanks. great for beginners

Thanks It helps to clear my fundamental

all clear ………very gud job !!!!

its really very usefull and understandable

Quike guide to understand the basics…great work…thanks a lot…

nice explanation

Good presentation.

Very good explanation. Thank you

thanku its very easy to understand and very easy explanation

thanq so much….its very nice …

awesome

please explain more sir,with example..

Good Summary. Thanks a lot!
A simple class diagram to explain the direction of the relationship would be great, if can be added

nice explanation. very useful. thanks

very nice explanation

Nice explanation of the terms…

nice definitions :)

pallabi baruah wake up!!!!listen to ur tech lead!!!

very nice explanation! keep it up

very nice explanation! keep it up

very good.

Goog Explanation. Keep going….

Thanks this helps !

thanks this really gives the clarity of this topic

thank u very much yar

Thanks you very much yar

very nice and better explain with subject examples also,its nice but iam feeling

Thanks this helps !

pls write about specialization also

very nice………
thank u so much

can you please explain opps concept in aquarium system? Means how can i explain an aquarium using OOPs

perfect..!!

One of good artical and understandable.

Great and a very simple way to explain a confusing subject. Thanks a lot for this Post.

GOOD and NICE and SIMPLE Explanation……..

Thanks for your inputs

good site thanks

Thanks very much nice information about Generalization, Aggregation, Association, Composition, Dependency,, only one time i have refereed to it but absolutely i got******

Looking forward to your next post like the same******* understandable

Nice one

the content is really very good..

nice information thank u logical examples have been provided

Really useful for beginners.
Thanks,

good information and very useful to the beginners .

thanks,

Good Information..

It will give an basic idea to all who dont have base knowledge on these.

From
Krs Rajasekhar

Good Information..

It will give an basic idea to all who dont have base knowledge on these.

From
Krs Rajasekhar

thanks a lot, you helped us completing our assignment. :)

Good explanations….

Good explanations….

Nice explanation yaar

Very nice content. I like it. The best site and very comprehensiveness information I ever found.

Simple and easy understandable writing. thanks alot for your effort.

Simple and very clear to understud thaks

Woow..very Nicely explained…

very nice

Sir what is the difference between generalization and specialization ??????

good article..

give me answer plz..
Justifying the statement ,”inheritance is a special case of Generalization”.

Thankyou… nice article.

Clean and clear explanation. Thanks a lot.

Thanks a lot for such an easy explanation. Examples are also easy to understand and correlate.

Thanks a lot Joe, Very Useful information with simple language and good examples.

nice explanation..

Nice Article Joe

I love your blog and find helpful…thanks for your great passion! You people make the world really great!

Nice and very helpful Article….

Thank you… nicely explained..!

nice simple article

The Post would become more clear if you difine these concepts in terms of object’s life Cycle.

Thanks
Nicely Explained

Very useful and complete

Best explained concept across the internet .
I was confused about those terms before reading these article . Thanks a lot. It’s helps me a lot.Will go through to other article.

Nice one Man!!

Good article.

thank you

First i was confused but now i am confidece
Thanks alot

very nice.. Thanks….

thanks for that and its very easy language

Very good explaination

good loooking web site sir…

thanks ..this is very good artical

help me alot….thks

Thanks for the explination. If a sample code is given it will become even more better.

Thanks in advance

Prem

Thanks for your good job…

good explaination joe, thanks

good explaination joe, thanks

sir,please give your mail id for further refrence..

ijust hv a doubt about composition ,as a example “A circle is composed of points”.
then i think points are exist without circle ,,but according to u points r not exist without circle ..plz explain.?

good answer and example

very Clear n nice explaination …
really confused before reading this article…
thank you!!

keep it up !!

very nice content to start
thanks

nice one

Hi Joseph,

This site is of great use for a java programmer like me.

Thank you so much.

really nice to see this site…

شكرا
Thanx

really nice. thanks!

very lucid and helpful. thank you.

In defining the Composition in top of page, I think the sentence should be
“…, if the container object cannot exist without the existence of contained object, then it is called composition”
instead of “…, if the contained object cannot exist without the existence of container object, then it is called composition”

I Think U are right Hikmat.

Good Article worth Reading. Nice Job!!!

Super explanation

Nice article.
Adding some example, hope till will support the article.
There are four kinds of Class relationships

Association: uses a
Ex:a Class Man uses a Class Pen
Aggregation: has a
Ex:a Class Man has a Class Car ( Car is still there when Man die )
Composition: owns a
Ex:a Class Man owns a Class Heart ( When Man die, Heart die )
Inheritance: is a
Ex:a Class Man is a Class Human ( Man is a Human )
A relationship between classes of objects

Inheritance>Composition>Aggregation>Association

excellent. i best site i found till now for jAVA.

its my OOMAD exam today and these definitions really made me relaxed regarding their easy understandibility.
Thnxxxxxx buddyyyyy

Could you please share with java code examples.

A implements B is realization
A extends B is generalization

AM I right?

Awesome

sir…you should use email validation in comment box…..
and your site content is awesome….i loved it….

Sir…it clearly differentiated the terms for a novice programmer.

Thanks!!:) It was really worthy.. Short & to the point.. Clarifying examples played vital role in understanding.. ‘Thanks’ once again..
_Js

Clear explanation with simplicity!
Thanks

Really a useful stuff to understand object relation ship.

Content is very good and the site is also looking so good keep it up sir,…

very helpful and easy understanding

it’s really good artical…..

thanks ji

hii thanks for information
kamal gaba

excellent clarified wit d example

Simply superb
Thank You

very nice it help me for my next interview :)

clearly understand, very good writing. Thank you.