Class diagrams in LLD - Architecture Diagram

System Overview - Class diagrams

A class diagram visually shows how different parts of a software system relate to each other. It helps us understand the structure by displaying classes, their attributes, methods, and how they connect.

Key requirements include clear representation of classes, their relationships like inheritance or association, and easy readability for developers.

Architecture Diagram

  +----------------+        +----------------+        +----------------+
  |    Class A     |        |    Class B     |        |    Class C     |
  |----------------|        |----------------|        |----------------|
  | - attribute1   |        | - attribute2   |        | - attribute3   |
  | + method1()    |        | + method2()    |        | + method3()    |
  +----------------+        +----------------+        +----------------+
          |                         |                         |
          | Inheritance             | Association             | Aggregation
          |                         |                         |
          v                         v                         v
  +----------------+        +----------------+        +----------------+
  |  Base Class    |        |  Class D       |        |  Class E       |
  +----------------+        +----------------+        +----------------+

Components

Class A

class

Represents an object with attributes and methods, inherits from Base Class

Class B

class

Represents an object associated with Class D

Class C

class

Represents an object that aggregates Class E

Base Class

class

Parent class providing common attributes and methods

Class D

class

Associated class used by Class B

Class E

class

Aggregated class used by Class C

Request Flow - 4 Hops

User → Class A

Class A → Base Class

Class B → Class D

Class C → Class E

Failure Scenario

Component Fails:Base Class

Impact:Classes inheriting from Base Class lose shared attributes and methods, causing errors or missing functionality

Mitigation:Refactor to use interfaces or composition to reduce tight coupling on Base Class

Architecture Quiz - 3 Questions

Which relationship shows Class A inherits from another class?

A Aggregation

B Inheritance

C Association

D Dependency

Design Principle

Class diagrams help visualize software structure by showing classes and their relationships like inheritance, association, and aggregation. This clarity aids in designing maintainable and scalable systems.