What are some examples of software design patterns that promote high cohesion and low coupling?

Remove the dependencies and allow class or function to work for single responsibility. Separate other responsibilities and do not allow different functions to be in a single class.

Facade and Strategy design patterns are examples that promote high cohesion and low coupling, aligning with the SRP; 🔸 Facade Pattern: This pattern provides a simplified interface to a complex subsystem. It decouples the subsystem from the client and other subsystems, promoting loose coupling. In a banking app, a MobileBankingFacade might provide simple methods like AccountInfo(), PaymentInfo(), which internally use complex subsystems. 🔸 Strategy Pattern: This pattern allows a strategy or algorithm to be selected at runtime. It promotes high cohesion as each strategy encapsulates an algorithm independently. In a banking app, a IPaymentStrategy interface could be implemented by CreditCardPayment.cs, DebitCardPayment.cs classes.

Model-View-Controller (MVC): This pattern separates an application into three interconnected components - Model (data logic), View (presentation layer), and Controller (user input handling). This promotes high cohesion by organizing code based on its purpose and minimizes coupling between different layers. Observer Pattern: It defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. This promotes low coupling because the subject (publisher) doesn't need to know anything about its observers (subscribers) except that they implement a specific interface. some other methods are Dependency Injection (DI), Adapter Pattern, Strategy Pattern & Facade Pattern.

The Single Responsibility Principle encourages a class to have only one reason to change, promoting high cohesion and low coupling. One example of a design pattern supporting SRP is the Repository Pattern. By isolating data access responsibilities into a dedicated repository class, the main class is freed from database-specific logic, enhancing cohesion and minimizing dependencies.

Cohesion and the Single Responsibility Principle both aim to improve software design by ensuring that modules and classes have well-defined, focused responsibilities. High cohesion leads to better adherence to SRP, resulting in a codebase that is more understandable, maintainable, and reusable.

The Open-Closed Principle emphasizes designing classes that are open for extension but closed for modification. The Strategy Pattern is an example of a design pattern aligning with OCP. By encapsulating varying behavior in separate strategy classes, the core class remains closed for modification while allowing easy extension by introducing new strategies.

Cohesion and the Open-Closed Principle work hand-in-hand to improve software design. High cohesion ensures that modules have clear and focused responsibilities, making them easier to manage. The Open-Closed Principle allows for extending the system's behavior without modifying existing code, promoting flexibility and reducing the risk of errors.

Factory Pattern: Decouples object creation from implementation, allowing easy swaps of class versions without impacting the client code. Observer Pattern: Allows objects to be notified of changes in another object, enabling independent evolution and clear responsibility separation.

The Adapter Pattern is an example of a design pattern supporting ISP. By creating adapters that implement specific interfaces, a class can selectively use adapters to interact with only the interfaces it requires, preventing unnecessary dependencies.

Dependency Inversion Principle (DIP) is a powerful design pattern for achieving high cohesion and low coupling in software design. By depending on abstractions rather than concrete implementations, software components become more modular and easier to manage. For instance, using an interface to interact with a database enhances flexibility and testability, as the components are not tightly linked to specific database implementations. In my experience, this approach not only simplifies updates and maintenance but also facilitates better testing environments, allowing for mock implementations during unit testing. This principle significantly contributes to a cleaner, more adaptable codebase.

The Dependency Injection Pattern aligns with DIP, allowing dependencies to be injected rather than created within a class. This promotes low coupling by enabling the use of different implementations without modifying the dependent class. We can apply the Dependency Injection Pattern using a DI container to inject dependencies. This practice allow us to adhere to DIP by ensuring that high-level modules depended on abstractions while remaining oblivious to the concrete implementations.

When considering software design patterns to promote high cohesion and low coupling, it's essential to emphasize overall system architecture, continuous refactoring, and adherence to SOLID principles. Regularly reviewing and adapting design patterns based on evolving requirements ensures a resilient and maintainable codebase.