Alternatives to Object-Oriented Programming?
OOP is probably the most used programming paradigm in today’s software design. My question is – what other paradigm(s) can compete with it and can stand in the place of OOP? To clarify that question, I’m not asking about what other paradigms there are. There are many of them, but I’d like to know which one…
- Has been used in practice, not only in theory.
- Can compete with OOP, so it can be used in a large project with a minimum of pain.
- Can be used to develop a desktop app with business logic, databases, and so on.
- Is not used alongside OOP, but as a replacement for OOP.
And if there is any, what are the pros/cons of it, why it is better/worse than OOP, what languages are the best to use it, what about using it in popular languages, has it any design patterns, and can it totally replace OOP?
Answer
Functional programming is another programming paradigm that is popular, mostly in academics. The best example of a functional programming language is Haskell and Standard ML.
The fundamental difference between functional programming and object oriented programming is that you are programming in the sense of data flow instead of control flow. See the presentation Taming Effects with Functional Programming by Simon Peyton-Jones for a good introduction.
A good example of functional programming used in the industry is Erlang. It is mostly used in telecommunication, distributed and fault tolerant systems. See the presentation Erlang - Software for a concurrent World by Joe Armstrong.
There are also newer functional programming languages that combine functional programming with OOP. Two good examples are F# for the .NET platform and Scala for the Java platform; they can often use existing libraries on the platform written in other languages.
The trend of new programming languages now is Multi-paradigm, where multiple paradigms like object oriented programming and functional programming are combined in the same language.