Objects owned by an aggregationassociation can be created without their owner and possibly could outlive him and serve another owner.
对象可以创建一个聚合协会旗下没有主人甚至可以比他和另一个主人服务。
2
For any two classes that have some relationship, identify the semantics of the relationship: is it association, aggregation, composition, or inheritance?
对于任意两个之间具有关系的类,确定关系的语义:是关联、聚合、合成还是继承?
3
Aggregation follows the same rules as association.