Behind the scenes of recursion?

Asked Oct 26 '15 at 21:07

Active Oct 26 '15 at 21:09

Viewed 46 times

so I've been recently studying recursion in Java, and while i fundamentally understand it, I don't quite have a grasp on what is happening behind the code. So for example, finding the factorial of 4.

public static long factorial(int n) {
    if (n == 0) // Base case
        return 1;
    else 
        return n * factorial(n - 1); // Recursive call
}

Can someone explain to me how the code would run. How does n* factorial(n-1) know what factorial(n-1) is equal to as it just recalled itself? I'm quite confused, any explanation would be appreciated, thanks!

edited Oct 26 '15 at 21:09

khelwood

55,782
14
81
108

asked Oct 26 '15 at 21:07

RiFF RAFF

2

Best solution: use pen and paper, lots and lots of paper, and step through the code on paper logically as if you were the computer. It also helps to understand the concept of a stack. – Hovercraft Full Of Eels Oct 26 '15 at 21:08
I'll try it cause thinking through it is hurting my head @HovercraftFullOfEels – RiFF RAFF Oct 26 '15 at 21:10
It will do that, but it is a worthwhile exercise. – Hovercraft Full Of Eels Oct 26 '15 at 21:11
To iterate is human, to recurse divine! – Jon Trauntvein Oct 26 '15 at 21:11
Also look at this [stack exchange q and a](http://programmers.stackexchange.com/questions/25052/in-plain-english-what-is-recursion) – Hovercraft Full Of Eels Oct 26 '15 at 21:11
Also see [this link](http://stackoverflow.com/questions/33355649/behind-the-scenes-of-recursion). ;) – Hovercraft Full Of Eels Oct 26 '15 at 21:14
Nothing linked @HovercraftFullOfEels – RiFF RAFF Oct 26 '15 at 21:15

Behind the scenes of recursion?

0 Answers0