Well, if we go by the Wikipedia definition of FP: > [It] treats computation as the evaluation of mathematical functions and avoids changing-state and mutable d

Well, if we go by the Wikipedia definition of FP: > [It] treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data. Javascript certainly doesn't avoid changing state or mutable data, as its two core data structures, objects and arrays, are both mutable.