Design Patterns Notes (6CS002) – Creational, Structural & Behavioral Patterns Explained

This document provides a comprehensive overview of design patterns in software engineering, focusing on their classification, purpose, and implementation. It covers three main categories of design patterns: creational, structural, and behavioural, along with decoupling patterns. Creational patterns such as Singleton, Factory, Abstract Factory, Builder, and Prototype are discussed in detail, highlighting how they provide efficient and flexible ways to create objects. Structural patterns including Adapter, Bridge, Composite, and Facade demonstrate how classes and objects can be combined to form larger and more flexible structures. Behavioural patterns like Strategy, State, Template, Decorator, and Visitor focus on improving communication and interaction between objects. The document also explains the advantages of using design patterns, such as improved code maintainability, faster development, and better system quality . Practical examples and Java implementations are included to illustrate how these patterns are applied in real-world scenarios, making the content useful for both learning and application in software development.