How to show multiplicities in UML object diagrams

Andrew picture Andrew · Feb 22, 2013 · Viewed 8.5k times · Source

I wonder if there is way to create an array of objects in UML?

the following is my try using Modelio as a modeling environment but as you can see there is different objects(i.e. instance[0],instance 1],instance[2],instance[3])

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Answer

jurgenreza picture jurgenreza · Feb 23, 2013

As you know there are two ways to show UML attributes in class diagrams: attribute text and association notation.

Consider an example of a company and employees. Two valid class diagrams are:

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Now let's try to draw the corresponding object diagrams:

If the details of the fulltime_employees like age are important, there is no other way but to show them as separate objects:

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If details are not important, we could go with attribute text notation:

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Another way of showing it when number of objects is more (let's say 5 here): (This is also the general way to show multiplicities in object diagrams)

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Hope it helps.