While recursion is a very good technique, it may face some problems due to details in the actual implementations. Each function call, recursive or not, requires an entry in the internal JS stack. When you are working with recursion, each recursive call itself counts as another call and you might find some situations in which your code will crash and throw an error, due to having run out of memory, just because of multiple calls. On the other hand, with most current JS engines, you can probably have several thousand pending recursive calls without a problem (but with earlier browsers and smaller machines, the number could drop into the hundreds and could imaginably go even lower), so it could be argued that at present, you are not likely to suffer from any particular memory problems.

In any case, let's review the problem and go over some possible solutions because, even if you don't get to actually apply them, they represent valid FP ideas for which you may find place...