What is recursion and how does it work?

Question

Could someone please explain what exactly recursion is (and how it works in Ruby, if that\'s not too much to ask for). I came across a lengthy code snippet relying on recurs

Answer 1

To understand recursion, you first need to understand recursion.

Now, on a serious note, a recursive function is one that calls itself. One classic example of this construct is the fibonacci sequence:

def fib(n)
  return n if (0..1).include? n
  fib(n-1) + fib(n-2) if n > 1
end

Using recursive functions gives you great power, but also comes with a lot of responsability (pun intended) and it presents some risk. For instance, you could end up with stack overflows (I'm on a roll) if your recursiveness is too big :-)