Jawaharlal Nehru Technological University Hyderabad B.Tech III DESIGN PATTERNS Previous Question Paper (July - 2023 - R16)

To select a design pattern, first identify the specific design problem or recurring challenge in the system architecture. Review the Intent section of candidate patterns to see if they address the identified problem, and compare the Consequences, trade-offs, and design constraints of each pattern to ensure it aligns with the system requirements. Finally, consider the Applicability and Related Patterns sections to determine if the pattern is suitable for the current context and how it might integrate with existing design structures.

A catalog of design patterns is a structured collection of proven solutions to recurring problems in software design. It serves as a standardized vocabulary for developers to communicate complex architectural decisions efficiently. The most influential catalog, introduced by the Gang of Four (GoF), categorizes 23 patterns into three primary groups based on their purpose:

• Creational Patterns: Deal with object creation mechanisms, aiming to create objects in a manner suitable to the situation (e.g., Singleton, Factory Method).
• Structural Patterns: Focus on object composition, defining how classes and objects are combined to form larger structures (e.g., Adapter, Composite).
• Behavioral Patterns: Concerned with algorithms and the assignment of responsibilities between objects, focusing on communication patterns (e.g., Observer, Strategy).

Each entry in a catalog typically includes the pattern's name, the problem it solves, the context in which it applies, the solution structure, and the consequences of its implementation.