UML - aggregation and association practical difference

Question

Hi, please is anybody here who can explain me the difference between aggregation and association in UML on some concrete C# example? I was looking on many websites for answer but everybody answers by theoretical examples like tree has a leaf and so on, but i still dont understand it, cos i dont know how it looks like in real code! for examle: public class SomeClass { private int someInt; private AnotherClass anotherClass; } What kind of relationship is between someClass and anotherClass? can you provide me code examples for all types of class relationship: association, aggregation, composition, generalization? MANY THANKS

jinge · Answer

Do not post duplicate thread.

Master Billa · Answer

Hi here is practical sample code given expert C# object 2008 book http://books.google.com.sg/books?id=8n7JD5me1CUC&pg=PA135&lpg=PA135&dq=aggregation+and+association+in+C%23+example&source=bl&ots=e2AGnXmyJ6&sig=plZCH7HXIejZmo3ZxTOyNSUahZs&hl=en&ei=b3vgSvPFJZOOkQW2j8wi&sa=X&oi=book_result&ct=result&resnum=2&ved=0CAoQ6AEwAQ#v=onepage&q=aggregation%20and%20association%20in%20C%23%20example&f=false thank you

Kirtan Patel · Answer

Friend , UML is Concept of Database Systems so it can be understandable by any programming language it can be only understandable by database terminology lets take example of Two Entity Customer and Loan Customer ( Cust_Id,Cust_Name,Cust_Address) and Loan ( Loan_Id,Amount); relation between Loan and Customer is "Customer-Loan" here Its Relation ship between Loan and Customer_ID but we need some additional information too :) thats Transaction Date So We can Take RelationShip "Customer-Loan" as Entity that will Store Transaction Date . so physically its entity in database but logically its Called Relationship so here Customer-Loan is said to be associative entity :) Aggregation ----------------- Lets take Example Entities are Bank , Employee ,Branch ,Manager here each Entity has one manager so instead of Showing relation Between each entity and Manager we can Represent Bank ,Employee ,Branch as One Group of Entity That related to Manager By Some Relation so here to representing Group is Called Aggregation if my answer helps you please check " Do you like this answer " :)

UML - aggregation and association practical difference

Answers (3)