Focuses on usage and need for Design Pattern. Before diving in, lets understand that
- Code is not an asset, it's a liability
- A genius admires simplicity while not sacrificing - readability, performance, maintainability, testability and reusability
Why Design Patterns?
- Beyond Code: Effective code goes beyond functionality. It should be:
- Readable: Easy to understand for you and other developers.
- Maintainable: Simple to modify and extend as your project evolves.
- Testable: Verifiable to ensure it works as expected.
- Reusable: Adaptable for use in different contexts.
A Pattern for Every Problem
Design patterns come in three main categories, each addressing specific coding scenarios:
- Creational Patterns: Focus on creating objects in a flexible and efficient way.
- Behavioral Patterns: Deal with how objects interact and communicate with each other.
- Structural Patterns: Emphasize how classes and objects are structured to form larger systems.
Choosing the Right Tool
Once you've identified a relevant category, ask yourself these questions to narrow down to the most suitable pattern:
Creational Patterns:
- Singleton: Do you need a single instance of a class throughout your application?
- Abstract Factory: Are you creating families of related objects?
- Builder: Is object creation complex, involving many optional parameters?
Behavioral Patterns:
- Strategy: Do you need interchangeable algorithms or behaviors for a particular operation?
- Command: Are you implementing undo/redo functionality, or want to encapsulate requests as objects?
- State: Do you need to manage the internal state of an object and how it changes its behavior?
Structural Patterns:
- Adapter: Are you trying to make incompatible interfaces work together seamlessly?
- Decorator: Do you want to add new functionalities to existing objects dynamically?
- Facade: Do you have a complex subsystem with many dependencies? A facade can simplify its interaction with other parts of your code.
There are many more patterns based on different use-cases.