What are the best strategies for reducing coupling in OOP code?

1 Use abstraction and encapsulation

One of the core principles of OOP is abstraction, which means hiding the implementation details of a class or module and exposing only its essential features and behavior. Abstraction reduces coupling by allowing you to change the internal logic of a class or module without affecting its consumers, as long as the interface remains consistent. Encapsulation is a way of implementing abstraction by restricting the access to the data and methods of a class or module, using modifiers such as private, protected, or public. Encapsulation ensures that the internal state of a class or module is not directly manipulated by other classes or modules, and that any changes are done through well-defined methods.

3 Favor composition over inheritance

Inheritance is a way of creating new classes or modules by extending the functionality of existing ones. While inheritance can be useful for reusing code and establishing hierarchies, it can also introduce tight coupling between the parent and child classes or modules, as any change in the parent can affect the child, and the child can access or override the parent's methods and data. Composition, on the other hand, is a way of creating new classes or modules by combining existing ones as components or attributes. Composition reduces coupling by allowing you to delegate the behavior of a class or module to its components, and to vary or replace them at runtime without affecting the class or module itself.

4 Use design patterns

Design patterns are reusable solutions to common problems in software design. They provide a common vocabulary and structure for designing and communicating your code, and help you avoid reinventing the wheel. Many design patterns can help you reduce coupling in your OOP code, such as the adapter, bridge, facade, mediator, observer, or strategy patterns. These patterns help you decouple different aspects of your code, such as the interface, implementation, logic, data, or communication, and make them more flexible and adaptable to changing requirements.

5 Refactor your code

Refactoring is the process of improving the structure and quality of your code without changing its functionality. Refactoring can help you reduce coupling in your OOP code by identifying and eliminating code smells, such as god classes, feature envy, shotgun surgery, or divergent change. These code smells indicate that your code is poorly designed, has too many responsibilities, dependencies, or changes, or violates the principles of cohesion and separation of concerns. By refactoring your code, you can extract, rename, move, or split your classes or modules, and make them more cohesive, modular, and easy to understand and maintain.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?