UML Class

A UML class is one of the key building blocks to create UML class diagrams.

It is represented as a card with three sections:

• A mandatory class name
• Optional Static/instance Attributes
• Optional Methods

Example of a UML class:

classDiagram
	class Dog {
		+String name
		+int age
		+void Bark()
	}

Class Name §

Defines the class. Abstract Classes have italicised class names.

UML Attributes §

A UML attribute must be defined with a name, and can have optional properties

Property	Syntax	Example
Name		$\text{xPos, size}$
Data Type	Name: [Data Type]	$\text{int,boolean}$
Initial value	Name: datatype = [Initial val]	$0,\text{null}$
Privacy/Visibility Modifier	[Privacy symbol] Name ... +PublicVar #ProtectedVar	+: Public ~: Default #: Protected -: Private
Multiplicity/Count	Name: Type[Multiplicity] in some cases Name[Multiplicity]: Type is used	$[n]$ = Finite $[a\dots b]$ = Finite Range $[a\cdots \ast ]$ Unknown Range $[\ast ]$ = Unknown Range (0+)
Static	[Underlined]	$\underline{\text{+Age: int}}$

UML Diagrams must only use primitive data types

Derived data types must be represented as a Class Relationship as well as the normal text. I.e. if we write name: CustomString, we also need to show a UML class CustomString, and some relationship between the two.

For example:

classDiagram
	class gameObj{
		-xPos: double
		-yPos: double
		-zPos: double = 0.0
		-count: int$
	}
	class Rectangle{
		-width: double
		-height: double
		-x: double = 0.0
		-y: double =0.0
	}

UML Methods §

Property	Syntax	Example
Name	[Name]()	$\text{Attack(), renderNew()}$
Privacy	[Privacy][Name]()	$+,\sim ,-,\#$
Return type	[Name](): [Type]	$\text{attack(): bool}$
Function (Computer Science) parameters	[Name]([Parameters])	$\text{attack(target: Object)}$
Static	Underline	$\underline{\text{defend()}}$
For example:

classDiagram
	class Cube{
		-position[3]: double
		-rotation[3]: double
		-scale[3]: double
		+Resize(newSize[3]: double) void
		+Move(newPos[3]: double) void
	}