What on Earth is Recursion? - Computerphile

> I still "see" the recursive function in line 23 just like a division by 2. Which obviously is not. Think of it as: “when I get to this point, I make a note of what I was doing, then evaluate `toBinary()` with half the original number as argument; once that is done, I insert that into my arithmetic expression and continue.” > I also don't get why in your example you basically never enter the base case of the function that should terminate it. Because we had already examined that case, so I just reused the previous result instead of going through it again. I have an idea. Take that code and type it in, if you haven't already. Then replace the last line of `toBinary()` with the following:…

This is a great 9 min video from computerphile that really helped me learn what recursion is. He uses the example of n! to illustrate his point. The best thing that this video taught me was that "there's not one n, but many." By this, he means that there every time the function calls itself, there is another scope set up in the call stack. Once you hit your base case, the result of the inner function is passed to the outer function all the way up the chain until the final n is returned. [video