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umldiagramrelationships

What double less sign mean in UML

I'm watching one course about programming, and found -->> uml diagram element, and can't find for what it stands for. I watched here, and here, and other places. But without success.

Please see attached image: enter image description here

Solution

  • For certain diagrams, Microsoft diverges from the UML standard by adding their own set of graphics. In the UML standard, multiplicity is only shown with numbers (UML Specification, 7.5.2), so the following answer is unique to Visual Studio, as standard UML provides no such syntax.

    This is from memory, but I think it serves me well in this case. Your screenshot is from Visual Studio. In VS, you can configure the multiplicity of an association by right clicking on the association and choosing show as collection association. In your case, this means that Rebate can have a collection of Tier, etc. This is also why the Property is pluralized next to the arrows (ProductGroups, Tiers, etc).

    Disclaimer: I don't have access to VS Ultimate anymore, so maybe the option in the context menu isn't worded in exactly that way, but it should be recognizable.