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General Discussion

Josh Keenan
Josh Keenan
20,315 Points
Posted by Josh Keenan
Josh Keenan
20,315 Points

Recursion

So I am a computer science student and have been for a while, but the actual usage of a recursive function does still seem to stump me 3/4s of the time, I understand the concept and can use it in some cases, but in others I might as well not be able to code at all.

Is there any resource anyone knows of that can help me get the hang of it?

1 Answer

Steven Parker
Steven Parker
231,269 Points
Steven Parker
Steven Parker
231,269 Points

There's just a few things to keep in mind when doing recursion:

  • by definition, the function must call itself under some condition(s)
  • there must be some other condition(s) where the function does not call itself
  • it must pass itself a different argument than it started with

For example, Here's a recursive function that adds together all integers up to one you specify:

function sumUpTo(n) {
    if (n == 0) return 0;
    return n + sumUpTo(n-1);
}

So it adds the argument to the result of calling itself with a smaller argument, unless (or until) the argument is 0. This particular task can be easily done without recursion, but it serves as a basic example of how recursion works.