Flow of C++ code

Question

Can someone explain the flow of this C++ code? I am having trouble understanding the flow, and why it flows the way it does.

#include <iostream>
using namespace std;

void func(int x)
{
if (x > 0)
{
func(--x);
cout << x;
}
else
{
return;
}
}

int main() {
func(5);
return 0;
}

Answer 1

/*
If you unwrap all the calls to func(5), it works very similar to this inline code:
*/
#include <iostream>
using namespace std;

int main() {
int x=5;
--x;
{ int x=4;
--x;
{ int x=3;
--x;
{ int x=2;
--x;
{ int x=1;
--x;
{ int x=0;
}
cout<<x; //0
}
cout<<x; //1
}
cout<<x; //2
}
cout<<x; //3
}
cout<<x; //4
return 0;
}

/*
The if statement that is used in the recursive function is there to determine when to stop nesting the calls and to start backing out. In this case, when x<=0.
*/

Answer 2

Some answers from this stackoverflow thread might help !

https://stackoverflow.com/questions/53022298/why-recursion-occurs-in-reverse#:~:text=This%20happens%20because%20each%20function,get%20printed%20in%20reverse%20order.

Answer 3

Brian, this is really neat, thanks! I think this is the most logical way to think about it, in code blocks.