How do you learn and update your skills on the open-closed principle in OOP?

The Open-Closed Principle (OCP), a fundamental concept in Object-Oriented Programming (OOP), states that software entities (classes, modules, functions, etc.) should be open for extension but closed for modification. This principle encourages the development of systems that are easily extendable over time without altering existing code, thus reducing the risk of introducing new bugs into a stable system. By adhering to OCP, developers can add new functionality by extending existing components, rather than changing the internal workings of those components. This leads to more robust, maintainable, and scalable software, as it promotes the use of interfaces and inheritance to enable flexibility and future growth.

First of all higher cohesion will not lead to less coupling. If a class does only one thing does it right in a system where multiple classes are involved it has to depend on the other classes thus increasing coupling. At the best we can balance them.

Firstly, I regularly study relevant literature, such as books and articles, focusing on OCP's principles and best practices. Secondly, I participate in online courses and tutorials offered by educational platforms, which often include practical examples and exercises to reinforce my understanding. Additionally, I explore open-source projects and review how experienced developers apply OCP in real-world scenarios. Lastly, I engage in discussions and exchange ideas with peers in programming communities, where I can share experiences, ask questions, and learn from others' perspectives, contributing to my continuous improvement in applying the Open-Closed Principle effectively.

Modifying existing code to introduce new functionality carries the risk of introducing regression bugs or unintended side effects. By adhering to the Open Closed Principle, you minimise the need for such modifications, reducing the risk of destabilising the system and improving overall reliability.

To effectively learn and update your skills on OCP, start by understanding its benefits: Decreased Coupling: Reduces dependencies between different parts of the code. Increased Cohesion: Enhances clarity and consistency within components. Flexibility: Adapts to changing requirements and user needs without major modifications. Ease of Maintenance: Simplifies testing, debugging, and extending code.

Applying abstraction is a key step in effectively implementing the Open/Closed Principle (OCP) in object-oriented programming. By focusing on the essential features and functionalities of a system while concealing its complexities, abstraction enables developers to define clear contracts through interfaces or abstract classes. This not only standardizes how similar classes interact but also encourages a clean separation of concerns, making the codebase more maintainable and extensible.

Abstraction allows developers to focus on what an object does instead of how it does it, facilitating easier understanding, maintenance, and extension of code. It leads to the creation of more generic, reusable components, reducing redundancy and improving software modularity. By using interfaces and abstract classes, abstraction enables polymorphism and dynamic binding, allowing for flexible and scalable system design. This principle significantly contributes to the development of high-level frameworks and libraries that abstract away the intricate details of underlying implementations, making software development more efficient and accessible.

Let us say a class "A" uses class "B" (either class "B" is passed as parameter to a function of "A" or is a state) and there is a requirement to have another class "B1" (a variation of B in behaviour) also can be swapped for "B" to work with "A" then an abstraction is made out of "B" and "B1" and this abstraction is used by "A". The abstraction "AB" can be an abstract class thus forcing inheritance or an interface. Examples are S.o.println of Java uses "Object" class's println method and we implement "toString" method in our classes to work with S.o.println. Here println is method closed for modification. Same with Arrays.sort method and we implement Comparable interface. Composition is not an alternative to inheritance but interface is.

These practices include writing clean and readable code, employing consistent naming conventions, and documenting code comprehensively. Developers are encouraged to embrace principles such as DRY (Don't Repeat Yourself) to avoid redundancy, and SOLID principles for object-oriented design to create more flexible, manageable systems. Regular code reviews, version control, and automated testing are crucial for early bug detection and ensuring code reliability. Best practices also emphasize the importance of continuous learning and adapting to new technologies and methodologies, fostering an environment of continuous improvement

For example, consider a scenario where you have a String class in C# and want to add a method to it to convert a string to title case. Without extension methods, you'd need to modify the String class itself, violating the OCP. However, with extension methods, you can create a separate static class with a method that operates on strings:

Have given examples from JDK above. There are more examples in JDK. People should stop saying "inheritance" means "code reuse". Actually many of the application code written by Java developers today are being used by simple (closed) methods of JDK written couple of decades ago by inheritance. New developers always think inheritance is going to help them write less code if they inherit from existing classes. But nobody goes on treasure hunt and write their own classes.

Examples serve as valuable references for solving common problems, encourage experimentation, and facilitate the learning of new programming languages or frameworks. This method also helps in bridging the gap between theory and practice, enabling developers to directly relate abstract concepts to tangible outcomes. Moreover, learning from examples promotes a deeper understanding of how different elements of code interact within a system, fostering a holistic view of software development. This approach is instrumental in accelerating the learning curve and enhancing problem-solving skills, making it a cornerstone of effective software engineering education and continuous professional growth.

This approach not only reinforces learning but also enhances problem-solving abilities by presenting challenges that require thoughtful solutions. Exercises range from simple coding problems to complex projects, catering to various levels of expertise and focusing on different aspects of software development, such as algorithms, data structures, design patterns, and application development. Engaging in regular practice helps in building confidence, improving coding proficiency, and staying updated with the latest technological advancements, thereby preparing developers for professional challenges and opportunities in the fast-evolving field of software development.