UML-question!

I would call code A for aggregation and
code B for association.

Hello!

But could you say that image 1 describes code B and image 2 describes code A, or the opposite, or not at all?

/Fredrik

code A = aggregation
code B = association
image 1 = aggregation
image 2 = composition

so image 1 matches code A

Hello!

Could you give me a example in code for composition, aggreagation and association?

I would say:
//Class that creates and keeps a reference to an other class = Composition
public class Class1
{
  Class2 class2;

  public Class1()
  {
    class2 = new Class2();
  }

}

----------------------
//Class that generates an other class but not keeps a reference = Aggregation
public class Class1
{

  public Class1()
  {
    method( new Class2() );
  }

}
-------------------------
//Class thats gets a reference to an other class but the other class is created somewhere else = Association.
public class Class1
{
  ClassX classX 

  public Class1(ClassX cX)
  {
    classX = cX;
  }

}

Or am I wrong????

Best regards

Fredrik

You are at least partly rigth.

A composition means that X owns Y.

public class X {
    private Y y;
    public X() {
        y = new Y();
    }
}

Noone else can use y.

An aggregation means that X has a reference to Y.

Example:

public class X {
    private Y y;
    public X(Y y) {
        this.y = y;
    }
}

Another class can also use y.

Association just means that X uses Y.

It can be composition or aggregation.

It can also just be other use.

Are you satisfied with the answer ?

Hello Amigo!

I am strugling with this but please hang on! I may add som question if that is OK.

Best regards
Fredrik

OK

Hello Arne!

I have made a new table to straighten this out at:

http://medlem.spray.se/fredand44/umltable.html

I would be most thankful if you could take a look at it and se if this is correct.

Best regards
Fredrik

It looks OK to me.

I can not guarantee that it is the ultimate truth.

But you will be able to argue your case.

Thanx mate!