软件工程类图_类图| 软件工程

柔光的暖阳◎ 2023-03-05 15:55 27阅读 0赞

软件工程类图

**Classes** are used to represent the object-oriented models. As we know that in the OOPs structure, every entity is treated as an object. A class thus can be defined as a collection of objects that share the common properties and behavior.

**类**用于表示面向对象的模型。 众所周知，在OOPs结构中，每个实体都被视为一个对象。 因此，一个类可以定义为共享共同属性和行为的对象的集合。

The **Class diagram of the software** consists of all the classes that exist in the software. In the class diagram, a class is represented via a rectangular box. Each of the classes is divided into three sections. The topmost section consists of the class name. The second section consists of the names of all the attributes that the class contains with their data types. And the third section consists of the methods (or functions) that are defined in the class. (It must be noted that the section of attributes and methods can be empty, but the class name cannot.)

**软件的** “ **类”图由软件**中存在的所有类组成。 在类图中，通过一个矩形框表示一个类。 每个类分为三个部分。 最上面的部分由类名称组成。 第二部分包括该类包含的所有属性及其数据类型的名称。 第三部分由类中定义的方法(或函数)组成。 (必须注意，属性和方法部分可以为空，但类名称不能为空。)

**For example:** Consider a **class** named "books" which has some attributes and methods. The class diagram for this very class would look something like this:

**例如：**考虑一个名为“ books”的**类** ，它具有一些属性和方法。 该类的类图如下所示：

![The class diagram in SE (1)][The class diagram in SE _1]

Here, **Books** is the name of the class, which has the following attributes: **BookId** of integer type, **BookCategory** of String type, **NumberOfBooks** of integer type, and has two methods namely: **AddBook()** and **AlterNumberOfBooks()**.

这里， **图书**是类，它具有以下属性的名称：整数类型的**BOOKID，**字符串类型的**BookCategory，**整数型的**NUMBEROFBOOKS，**并有两个方法，即**：AddBook()**和**AlterNumberOfBooks()。**

Now, **the class diagram** not only consists of the classes, but these classes also hold some relation with each other, and this relation is also represented in this diagram.

现在， **类图**不仅由类组成，而且这些类之间也具有某种关系，这种关系也在此图中表示。

A class is connected with another class (with whom it holds a relation) using a single line, and on that line, we represent the cardinality. The cardinality represents the number of entities that exist in the relation. It may be one to one, one to many, etc. The cardinality symbols are represented as follows for a class:

一个类使用单行连接到另一个类(与其保持联系)，并且在那一行上，我们表示基数。 基数表示关系中存在的实体数。 它可以是一对一，一对多等。对于一个类，基数符号表示如下：

![The class diagram in SE (2)][The class diagram in SE _2]

Image source: https://wcs.smartdraw.com/class-diagram/img/notes.jpg?bn=1510011152

图片来源：https://wcs.smartdraw.com/class-diagram/img/notes.jpg?bn=1510011152

**Example:**

**例：**

Let us consider the example of the library management system. The following is the class diagram for the same.

让我们考虑图书馆管理系统的示例。 以下是相同的类图。

It consists of nine classes that are interconnected. The relations and cardinality of each of them can also be inferred from the class diagram itself.

它由九个相互关联的类组成。 它们每个的关系和基数也可以从类图本身推断出来。

![The class diagram in SE (3)][The class diagram in SE _3]

**Class Diagram for library management System**

**图书馆管理系统的类图**

> 翻译自: [https://www.includehelp.com/basics/the-class-diagram-software-engineering.aspx][https_www.includehelp.com_basics_the-class-diagram-software-engineering.aspx]

软件工程类图

[The class diagram in SE _1]: /images/20230208/462de04aa9374a56b240b1524e1ed1fb.png
[The class diagram in SE _2]: /images/20230208/ad581de6f4b14fdb8dd1c6904a57805b.png
[The class diagram in SE _3]: /images/20230208/c113c6494aba40fab2b16b5cc12842e5.png
[https_www.includehelp.com_basics_the-class-diagram-software-engineering.aspx]: https://www.includehelp.com/basics/the-class-diagram-software-engineering.aspx