mermaid

FlowChart

```mermaid
	graph TD
	A-->B
```

方向

• TB 从上到下
• BT 从下到上
• RL 从右到左
• LR 从左到右
• TD 同 TB

基本图形

• [带文本的矩形]
• (带文本的圆角矩形)
• >带文本的不对称的矩形]
• {带文本的菱形}
• ((带文本的圆形))

如果节点的文字中包含标点符号，需要时用双引号包裹起来

```mermaid
graph TD
    A[带文本的矩形]
    B(带文本的圆角矩形)
    C>带文本的不对称的矩形]
    D{带文本的菱形}
    E((带文本的圆形))
```

结点间连接

• A --> B A 带箭头指向 B
• A --- B A 不带箭头指向 B
• A -.- B A 用虚线指向 B
• A -.-> B A 用带箭头的虚线指向 B
• A ==> B A 用加粗的箭头指向 B
• A -- 描述 --- B A 不带箭头指向 B 并在中间加上文字描述
• A -- 描述 --> B A 带箭头指向 B 并在中间加上文字描述
• A -. 描述 .-> B A 用带箭头的虚线指向 B 并在中间加上文字描述
• A == 描述 ==> B A 用加粗的箭头指向 B 并在中间加上文字描述

子流程图

```mermaid
subgraph title
    graph definition
end
```

Demo

```mermaid
	graph LR
    start[开始] --> input[输入A,B,C]
    input --> conditionA{A是否大于B}
    conditionA -- YES --> conditionC{A是否大于C}
    conditionA -- NO --> conditionB{B是否大于C}
    conditionC -- YES --> printA[输出A]
    conditionC -- NO --> printC[输出C]
    conditionB -- YES --> printB[输出B]
    conditionB -- NO --> printC[输出C]
    printA --> stop[结束]
    printC --> stop
    printB --> stop
​```

Class Diagram

```mermaid
	 classDiagram
      Animal <|-- Duck
      Animal <|-- Fish
      Animal <|-- Zebra
      Animal : +int age
      Animal : +String gender
      Animal: +isMammal()
      Animal: +mate()
      class Duck{
          +String beakColor
          +swim()
          +quack()
      }
      class Fish{
          -int sizeInFeet
          -canEat()
      }
      class Zebra{
          +bool is_wild
          +run()
      }
```

定义类

1. 使用关键字 class
2. 使用关系符 <|-- 定义两个类的关系

classDiagram
    class Animal
    Vehicle <|-- Car

定义属性、方法

Mermaid distinguishes between attributes and functions/methods based on if the parenthesis () are present or not

1. 使用 :
2. 使用 {}

 class BankAccount
 BankAccount : +String owner
 BankAccount : +BigDecimal balance
 BankAccount : +deposit(amount)
 BankAccount : +withdrawal(amount)
 
 class BankAccount{
    +String owner
    +BigDecimal balance
    +deposit(amount)
    +withdrawl(amount)
}

函数返回值

写在函数后

+withdrawl(amount) int

设置泛型

使用 ~~ 包围

classDiagram
class Square~Shape~{
    int id
    List~int~ position
    setPoints(List~int~ points)
    getPoints() List~int~
}

Square : -List~string~ messages
Square : +setMessages(List~string~ messages)
Square : +getMessages() List~string~

设置成员可视类型

• + Public
• - Private
• # Protected
• ~ Package/Internal

note you can also include additional classifiers to a method definition by adding the following notations to the end of the method, i.e.: after the ():

• * Abstract e.g.: someAbstractMethod()*
• $ Static e.g.: someStaticMethod()$

类关系

[classA][Arrow][ClassB]:LabelText

Type	Description
<|--	Inheritance
*--	Composition
o--	Aggregation
-->	Association
--	Link (Solid)
..>	Dependency
..|>	Realization
..	Link (Dashed)

Entity Relationship Diagrams

erDiagram
    CUSTOMER ||--o{ ORDER : places
    ORDER ||--|{ LINE-ITEM : contains
    CUSTOMER }|..|{ DELIVERY-ADDRESS : uses

<first-entity> [<relationship> <second-entity> : <relationship-label>]

Value (left)	Value (right)	Meaning
`	o`	`o
`		`
}o	o{	Zero or more (no upper limit)
`}	`	`