Java has been multi-paradigm since the beginning, although it favours a stateful style for sure. FP is by no means restricted to purely functional languages. M

Java has been multi-paradigm since the beginning, although it favours a stateful style for sure. FP is by no means restricted to purely functional languages. My impression is that the ideal approach is to use the paradigm most suitable for the problem/component at hand (principle of least expressivity), so I prefer multi-paradigm languages over pure ones, although of course I understand that there are domains where one can benefit from the optimizations made possible by purity. Understanding how to do this requires much more of a learning effort, learning more concepts, techniques and idioms, which I suspect is why FP is still lagging; I don't believe it is for any fundamental reason. The other thing is that there are many more programming paradigms than just functional and stateful.