What are the trade-offs between OOP and functional programming?

The trade-offs between OOP and functional programming involve differences in state management, modularity, and code readability.

Object-Oriented Programming (OOP) and Functional Programming (FP) are two different paradigms that offer unique ways to structure and organise code. OOP is centred around objects and their interactions, making it a natural fit for applications that model real-world objects or systems. It's excellent for creating complex, large-scale systems due to its emphasis on modularity and code reusability. However, managing state in OOP can be tricky, as objects maintain state. This can lead to issues with data consistency and bugs that are hard to trace.

On the other hand, FP treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data. This makes it great for applications that require a high level of concurrency or need to handle a lot of data. FP can lead to safer, more predictable code, as functions have no side effects. However, FP can be more challenging to grasp, especially for beginners, as it requires a different way of thinking compared to the more intuitive, 'real-world' model of OOP.

In terms of modularity, both paradigms offer ways to break down code into reusable parts. OOP uses classes and objects, while FP uses functions. However, the way these parts interact differs. In OOP, objects can interact and communicate with each other, which can lead to complex and tangled dependencies if not managed well. In contrast, FP functions are independent and don't interact with each other, leading to a more straightforward flow of data and easier debugging.

Code readability is another area where trade-offs can be seen. OOP code can be more straightforward to read and understand, as it models real-world concepts. However, it can also become convoluted due to inheritance and polymorphism. FP code can be more concise and easier to test due to its stateless nature, but it can also be harder to understand due to its abstractness and heavy use of recursion.

In conclusion, the choice between OOP and FP depends on the specific needs of the project, the team's familiarity with the paradigms, and the problem being solved. Both have their strengths and weaknesses, and understanding these trade-offs can help in choosing the right approach.