Design Pattern

Design patterns are pre-made solutions to common software design problems.

They provide blueprints that you can customize for your specific needs.

• Difference from Functions/Libraries:

  • Unlike off-the-shelf functions or libraries, you can't simply copy-paste a design pattern into your code.

  • Design patterns are conceptual solutions rather than specific lines of code.

• Pattern vs Algorithm:

  • Algorithms are step-by-step procedures to achieve a specific goal.

  • Patterns are higher-level descriptions of solutions; they're more like blueprints than recipes.

• Pattern Components:

  • Intent: Briefly describes the problem and solution.

  • Motivation: Further explains the problem and the solution the pattern offers.

  • Structure of Classes: Shows how different parts of the pattern relate to each other.

  • Code Example: Provides a practical illustration in a popular programming language.

• Additional Pattern Details:

  • Some pattern catalogs include applicability, implementation steps, and relations with other patterns.

Design patterns vary in complexity, detail, and applicability across the system.

Analogy: Similar to road construction, where you can enhance safety at an intersection by either adding traffic lights or constructing a multi-level interchange.

Levels of Patterns:

• Idioms: Basic and low-level patterns specific to a programming language.

• Architectural Patterns: Universal and high-level patterns applicable across different languages. They can shape the architecture of an entire application.

Categorization by Intent:

• Creational Patterns: Focus on object creation mechanisms to enhance flexibility and code reuse.

• Structural Patterns: Describe how to organize objects and classes into larger structures, maintaining flexibility and efficiency.

• Behavioral Patterns: Handle effective communication and delegation of responsibilities among objects.