Shulou(Shulou.com)06/02 Report--

This article will explain in detail several views about UML, which the editor thinks is very practical, so I share it for you as a reference. I hope you can get something after reading this article.

Introduction to nine views of UML

First of all, give a brief introduction to the functions of each diagram in UML:

1. Use case diagram

Describe roles and the connections between roles and use cases. It shows who wants to use the system and what they can do with it. A use case diagram contains multiple model elements, such as systems, actors, and use cases, and shows the relationships between these elements, such as generalization, associations, and dependencies.

2. Class diagram

Among the nine views of UML, a class diagram is a static view that describes the classes in the system and the relationships between them. It allows us to have a comprehensive understanding of the system before we write the code correctly. A class diagram is a model type, or rather, a static model type.

3. Object graph

Very similar to a class diagram, it is an instance of a class diagram, which shows multiple object instances of a class rather than the actual class. It does not describe the relationship between classes, but the relationship between objects.

4. Activity diagram

Describing the activities required by the use case, as well as the constraint relationship between the activities, is helpful to identify parallel activities. It can demonstrate where functions exist in the system and how these functions and the functions of other components in the system work together to meet the business requirements modeled previously using use case diagrams.

5. State diagram

In the nine views of UML, the state diagram describes all possible states of the object of the class, as well as the transition conditions of the state when the event occurs. The lifecycle of objects, subsystems, and systems can be captured. They can tell the states that an object can have, and how events (such as the receipt of messages, the passage of time, errors, conditions become true, etc.) affect these states over time. A state diagram should be connected to all classes that have a clearly identifiable state and complex behavior; the diagram can determine the behavior of the class and how the behavior changes according to the current state. It can also show which events will change the state of the class's objects. The state diagram is a supplement to the class diagram.

6. Sequence diagram (sequence diagram)

A sequence diagram is a model that shows how your actors interact with the objects of the system in a series of sequential steps. Sequence diagrams can be used to show how objects interact with each other. The sequence diagram focuses on the message sequence, that is, emphasizing how messages are sent and received between objects.

7. Collaboration diagram

Similar to the sequence diagram, it shows the dynamic cooperative relationship between objects. It can be seen as the intersection of class diagrams and sequence diagrams, collaboration diagrams modeling objects or roles, and how they communicate with each other. If time and sequence are emphasized, sequence diagrams are used; if superiors and subordinates are emphasized, collaboration diagrams are selected; together, these two diagrams are called interaction diagrams.

8. Component diagram (component diagram)

Component diagrams in the nine views of UML describe the physical structure of code components and the dependencies between various builds. Used to model the components of the software and their relationships with each other, these diagrams are made up of component markers and relationships between components. In the component diagram, the component is a single part of the software, it can be a file, product, executable file, script and so on.

9. Deployment diagram (configuration diagram)

Is used to model the physical deployment of the system. For example, computers and devices, and how they are connected. Deployment diagrams are used by developers, system integrators, and testers.

The differences between the nine views of UML:

One: each of the nine model drawings has its own emphasis.

1: use case diagrams focus on describing user requirements

2: the class diagram focuses on describing the specific implementation of the system.

Two: the nine views of UML describe different aspects.

1: the class diagram describes the structure of the system.

2: the sequence diagram describes the behavior of the system.

Three: the levels of abstraction of the nine views of UML are also different.

1: the component diagram describes the module structure of the system with a high level of abstraction.

2: the class diagram describes the structure of concrete modules, and the level of abstraction is general.

3: the object graph describes the specific module implementation, and the level of abstraction is low.

In some literature and books, these nine model diagrams are divided into three categories:

Structural classification, dynamic behavior, and model management:

1: structure classification includes use case diagram, class diagram, object diagram, component diagram and deployment diagram

2: dynamic behaviors include state diagrams, activity diagrams, sequence diagrams and collaboration diagrams.

3: model management includes class diagrams.

This is the end of this article on "there are several views of UML". I hope the above content can be helpful to you, so that you can learn more knowledge. if you think the article is good, please share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.