java - "is unique"Eclipse UML 代表什么？

Question

我实际上是在 eclipse 上设计 UML，我只是在变量模型属性上遇到一个“是唯一的”复选框。这是什么意思？同一个类中的每个变量不应该是唯一的？

Answer 1

我将简单地引用 p.1 上的 UML 规范。 34 在这里:

If the MultiplicityElement is specified as unique (i.e., isUnique is true), then the collection of values in an instantiation of this Element must be unique. That is, no two values in the collection may be equal, where equality of objects (instances of Classes) is based on object identity while equality of data values (instances of DataTypes) and Signal instances is based on value (see also sub clauses 10.2, 10.3, and 11.4 on DataTypes, Signals and Classes, respectively ). If a MultiplicityElement is not multivalued, then the value for isUnique has no semantic effect.

Taken together, the isOrdered and isUnique properties can be used to specify that the collection of values in an instantiation of a MultiplicityElement is of one of four types. Table 7.1shows the traditional names given to each of these collection types.