invarian(不变条件) 限制操作中,类中某个条件不会变,如一个账户,在增加xx钱,再减少xx钱,余额是一定的。 补充1:聚集(aggregation)和组合(composition),这个是需要从上下文的语义关系才能看出来的。聚集的意思是:当需要对“整体/部分”关系建模时,其中一个类描述了一个较大的事物(“整体”),它有较小的事物(“...
在UML类图中,常见的有以下几种关系:泛化/继承(Generalization), 实现(Realization),关联(Association),聚合(Aggregation),组合(Composition),依赖(Dependency) 类图基本属性 类在UML类图中,类使用包含类名、属性(field) 和方法(method) 且带有分割线的矩形来表示。例如下图Person类,包含了name... ...
In software engineering, a class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects. 在软件工程中,类图在统一...
In software engineering, a class diagram in the Unified Modeling Language (UML) is a type of static structure diagram that describes the structure of a system by showing the system's classes, their attributes, operations (or methods), and the relationships among objects. 在软件工程中,类图在统一...
In UML there are two kinds of aggregations:aggregation and composition.An aggregation ,also called relation aggregation is a specialised association.It is specified by an aggregation association with a hollow diamond.A part in thie type of aggregation can participate in several aggregates. ...
In design, these can become aggregation or composition relationships We must also add navigability, multiplicity and role names A B A B A B ?trace? ?trace? {xor} Analysis Design aggregation composition Aggregation and composition Some objects are strongly related like a tree and its leaves Some...
Class Diagram provides an overview of the target system by describing the objects and classes inside the system and the relationships between them. It provides a wide variety of usages; from modeling the domain-specific data structure to detailed design
There are two special association cases: aggregation and composition. These are represented, respectively, by an empty and a filled-in diamond on the aggregate side. In our example, a composition relationship links the places (the class Place) to their Territory (aggregate). Read more View ...
//Aggregation Class Pond{ private: std::vector<Duck*> ducks; // 当vector 的析构函数被调用时,duck实例并不会被销毁 } Composition 组成(Composition)关系,是一类“强”的整体与部分的包含关系(" ... is a part of ...")。成分类必须依靠合成类而存在。整体与部分是不可分的,整体的生命周期结束也就...
Composition: A special type of aggregation where parts are destroyed when the whole is destroyed. Objects of Class2 live and die with Class1. Class2 cannot stand by itself. A solid line with a filled diamond at the association connected to the class of composite Dependency: Exists between...