UML Notation Reminder: Multiplicity and Ordering
The multiplicity of a class relationship indicates, for an instance of either class, how many instances of the other class it may be related to.
- A range is specified as [lower limit]..[upper limit], where an asterisk for the upper limit indicates that there is no upper limit.
- An asterisk by itself means "zero or more".
- For an exact number (lower_limit = upper_limit), the number is given.
When more than one component may be present and the order of the component instances carries semantic information, the component end of the class relationship is marked with {ordered}.
lower_limit_a .. upper_limit_a
lower_limit_b .. upper_limit_b