Once a bunch of objects have been created in a system, data modifing become common maintenance. A modify is the special interaction that makes something change. The examples below show that in a zoo, the zoologists maintain the pandas' records updated.

In figure:1, the resource object class "zoologist" have to modify the destination object class -- "name of panda". Since the destination object class may have many objects, we must choose one to modify. We use clause TO to show which one we want.( say we want to change panda named "rose" to "dahlia". )

Or we may sometimes use shorthand form to put the clause TO into interaction description as in figure:2.

We may even omit the whole interaction as a very shorthand form if the problem is easy.

In fact, the destination object class may be a singleton or high-level object class and what we need to modify may be a bunch of data. figure:4 below shows that a high-level object class "panda" has records to update.

When analysis, we do not need to take care how system establish the new relationship after modification. What we should think about is make sure what we want to change and where to change.

Here is a short quiz so you can test your understanding of modify.

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Created Thurs Oct. 6 16:28:10 1994 ...
Updated Thurs Nov. 23 13:25:12 1994
by Wei Wei (