Week 5 - Recursion

Recursion is used in order to repeat a similar task a (obviously) finite number of times. More specifically in code, this can be done by having a function to call itself. The thought is to divide up a problem into smaller parts and calculate those individually to finally get the answer as a whole.

For example, let's start with the most basic example of recursion I can think of:

def factorial(number):
    if number == 1:
        return 1
    return number*factorial(number-1)


Nothing complicated here, it was annoying enough to write it in this blog...Maybe next time I'll just put a screenshot of some code in an IDE. That would probably be easier.

The first part would be a base case for when the recursive function will simply return a result without going through any more iterations involving recursion. But before reaching the base case the function would call on itself in order to execute more steps recursively.

I had previously already encountered and learned about recursion so it was not difficult for me to understand it. Different syntax but not much change. I recall when I had first learned about recursion it would definitely help if I would actually write down each step on a piece of paper and go through the results backwards to see how the code works. Now I don't really have to do that with the rather simple examples we learned in class but it still is a good thing to learn. (The exercise/worksheet we did in class was pretty close to what I described but starting with multiple simpler examples instead of going through a more difficult one at the start) All in all recursion is a great concept and tool to learn and even though I know it can be incredibly difficult for some people to grasp at the beginning, at least they can be assured that it will be of great benefit to learn.