[Uml-devel] UML question

[Lea Anthony]

Hi Steinchen,

What I mean is, there is a definate distinction between relationships and 
aggregations. Relationships have straight lines and aggregations are the same 
but with diamonds on the end. So given that, what's the difference between a 
1 to many relationship and a 1 to many aggregation. I think the answer is 
that a class exists in it's own right when a 1 to many relationship is used, 
but when an aggregation is used, it means the class is _comprised_ of that 
aggregate too. 

I think, a car would have a 1...*  aggregation of wheels, but not a 1...* 
aggregation of persons. 

If that makes any sense...

-Lea.

On Sunday 25 May 2003 19:05, Sebastian Stein wrote:
> Lea Anthony <lea at fluidenterprises.co.uk> [030523 19:51]:
> > I've been looking at UML more lately and have a simple question: What's
> > the difference between a 1..* relationship and an aggregation?
>
> Well, I'm not really sure what you mean, because I think you are mixing
> some things... 1..* is called multiplicity (better known as cardinality).
> An aggregation could have 1..* multiplicity. This means, that class A could
> have an unfinite number of objects of class B.
>
> Steinchen