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Today, I would like to talk to you about how to understand UML. Many people may not know much about it. In order to make you understand better, the editor has summarized the following contents for you. I hope you can get something from this article.

What is UML?

Unified Modeling Language (Unified Modeling language) is a general and visual modeling language standard developed by the international object management organization OMG, which can be used to describe various artifacts (artifacts) of software-intensive systems such as specify, visualize, construct and document.

What are the characteristics of UML?

The "versatility" of UML mainly means that it can be used not only to describe software, but also to describe the business processes of general enterprises or organizations and software-based complex systems composed of software and hardware (so-called software-intensive systems), and even non-software systems.

The "visibility" of UML means that many complicated concepts in system analysis and design can be intuitively and clearly expressed through a series of graphic symbols of UML to form multiple views (view). UML is mainly designed for people to read and use, so it adopts a semi-formal form that is easy for people to understand and communicate.

UML is a special modeling language for analysis and design. It is not a programming language and can not be directly used to generate executable software. UML is a graphic language with a higher level of abstraction than C, C++, Java, VB, Delphi and other high-level text languages. Through it, we can abstractly represent the logical structure and behavior of text programs written in high-level programming languages. Compared with the traditional high-level programming language, UML can reflect the scheme and idea of software design more efficiently and accurately, and it is the language really used to "design program" (design programs). In this sense, UML can be called a "very high-level" programming language.

Basically, UML can not be regarded as a brand-new invention, it is not the research results of scholars, professors and scientific research institutions, but directly from the practical summary of industry and engineering, and the product of theoretical sublimation on the basis of induction. Its core content reflects the practice and successful experience of the global software industry in the field of software design and construction for more than 30 years, so it has high practical value.

Practice has proved that the OO Analysis and Design (OOAD) method can describe the real world more accurately and comprehensively than the traditional method. UML is a language tool used to express the concept of OO, and it is wonderful. As a product, it is also designed by OO method, which makes UML have strong semantic expression ability and flexible expansibility that traditional modeling languages do not have.

What's the use of UML?

UML has a wide range of uses, which can be summarized as four basic functions of "description, visualization, construction and recording". It can be used in business modeling, requirement analysis, system design, implementation and testing, data modeling, project management and other phase tasks.

UML modeling is an effective means to establish software development documents. Visually describing system requirements and recording software composition through UML can significantly improve the quality and readability of documents and reduce the workload of writing documents.

UML is essentially a special language for system analysis and design. Visual graphical symbols combined with text descriptions or tags can help various modelers, such as business / system analysts, software architects / designers, programmers, to effectively describe the static structure and dynamic behavior of complex software (or business). It includes workflow (data flow and control flow), functional requirements, structural elements and relationships, architectural composition, design patterns, object collaboration, event response, state change, and so on.

What can't UML do?

UML is not a highly formal language and generally can not be used for theorem proof.

UML is a general modeling language based on OO method, which is not suitable for user graphical interface design, very large scale integrated circuit (VLSI) design, rule-based artificial intelligence and other professional fields.

UML is a discrete modeling language, which is suitable for modeling discrete systems composed of software, firmware or digital logic, but not for continuous systems in the fields of engineering and physics.

As a language, UML is only a form of expression, not a modeling method. It is far from enough to master a set of standard graphical symbols in actual software project development. To make good use of UML, we first need to master the basic principles and methods of OOAD, and use it under the guidance of a certain software development process (such as UP/RUP, XP, etc.).

Why learn and master UML?

First of all, UML is essential or necessary for most current software development teams that want to further improve quality. Why do you say that? Because C++, Java and other source code can not directly and conveniently reflect the design of complex programs, such as the internal logical structure, a variety of implicit dependencies, runtime state changes and special behavior, and so on. Written code is only an implementation, and it is difficult to reflect the true nature behind the phenomenon-design, so for most slightly more complex projects, code alone is not enough.

Visual modeling has always been a successful engineering practice, which is not unique to the software industry. Software design is usually hidden in people's minds before it is implemented with C++ and Java, and whether the design is correct or not is the key to determine the quality of the software. A premise is that it must be expressed in an appropriate way. It is often clumsy to express, discuss, evaluate and select the design of complex software through program code, and the gap of this expression can only be filled by modeling languages like UML.

Secondly, OO method is the mainstream software development technology. The advanced software teams and individuals in the world have already got rid of the entanglement about how to use the specific platform API and individual programming language features, and put more energy on the core elements, analysis and design, such as requirements, architecture, design mechanisms and patterns, which have a great impact on software quality. As the de facto standard and main expression medium of OO modeling language, UML can play a key role in these situations. Therefore, skillfully mastering and making good use of UML is a basic skill for today's system analysts, architects / designers, programmers and other software engineers.

After reading the above, do you have any further understanding of how to understand UML? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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