Class Diagram: A class diagram is like a blueprint that describes the structure and behavior of a system. It’s a static view, meaning it shows the relationships and attributes of classes at a specific point in time.
Key Points:
- Static Representation: It gives a static snapshot of the classes and their relationships.
- System Structure: Describes how classes are organized and connected in an application.
- Visualization and Documentation: Used for visualizing, describing, and documenting various aspects of a system.
- Attributes and Operations: It outlines the properties (attributes) and actions (operations) of a class.
- Object-Oriented Mapping: Commonly used in object-oriented systems, aligning with object-oriented programming languages.
Example: Consider a “Party” class with attributes like “location” and relationships like “parent” and “children.” Here’s a simple class diagram:
Object Diagram: An object diagram is like taking a photograph of your class diagram at a particular moment, showing instances (objects) and their relationships.
Key Points:
- Instance Representation: Represents instances (objects) of classes from a particular point in time.
- Static Snapshot: Still a static view, but focused on the current state of the system.
- Rendering Instances: Displays a set of objects and their relationships as they exist in a specific scenario.
Example: Taking the “Party” class example, an object diagram shows instances of this class:
