Recursion

In the previous post I talked about OOP. The main advantages of the OOP paradigm is that it offers data encapsulation and polymorphism. Data encapsulation separates interface from implementation and polymorphism lets a whole system of data behave as one. A competing language design paradigm is 'functional programing'. In this framework objects have no notion of identity or mutable state. The consequence of this last feature is heavy use of recursion. Recursion is the idea that we can solve a big problem by breaking them down into smaller, self-similar, subproblem. Therefore recursive functions take in the return value of their own return call (recursive call). Recursion is related to mathematical induction and in the most simple case a recursive needs a base case and a recursive case. Base case produces a result without recurring and recursive case divides the problem into a smaller subproblem. The base case is sometimes called the terminating case and the job of the recursive case is to breakdown the problem such that the terminating case is eventually reached and the problem is solved.