Object Diagram

About

An Object Diagram in UML represents a snapshot of instances (objects) and their relationships at a particular moment in time. It is a real-world instantiation of a Class Diagram, showing actual values instead of abstract structures. Object Diagrams help in visualizing runtime scenarios of a system, such as debugging, testing, or understanding object interactions.

Refer to the official documentation for more details - https://plantuml.com/object-diagram

Key Elements

1. Objects (Instances)

   • Represented as rectangles with an underlined name (e.g., order1: Order).

   • Shows real-time values of attributes.

2. Links (Associations)

   • Lines connecting objects to represent relationships.

   • These are actual instance-level associations, unlike general class associations.

3. Attributes & Values

   • Shows specific values of attributes at runtime (e.g., status = "Processing").

4. Multiplicity & Relationships

   • Displays one-to-one, one-to-many, or many-to-many relationships.

5. Aggregation & Composition

   • Can illustrate part-whole relationships between objects.

1. E-commerce system

This represents the state of objects at runtime in an e-commerce system.

• Objects (object ObjectName { }).

• Relationships (--): Shows how objects are related at runtime.

@startuml
title E-Commerce Order - Object Diagram

object Customer {
    name = "John Doe"
    email = "[e-mail]"
}

object Order {
    orderId = 12345
    totalAmount = 150.00
}

object Product {
    name = "Laptop"
    price = 1500.00
}

Customer -- Order : places
Order -- Product : contains

@enduml