How does this recursion loop code executes

Question

I have some line of code where i cannot understand how the codes are executes, i mean the flow of program.

Code:

1) public class RecurLoopTest {

2)  public static void main(String[] args) {
3)      printit(2);
4)  }

5)  private static int printit(int n){
6)      if(n>0){
7)          printit(--n);
8)      }

9)      System.out.print(n+",");

10)     return n;
11) }

12) }

I am thinking output should be: 0,

But Output is: 0,0,1,

I have done DEBUG above class so many time, The flow i have seen while debugging:

1. Starts execution from line 3, i.e. invokes printit() with 2 as parameter.
2. line 6, if condition checks n value if greater than zero, then controls goes to line 7, i.e. prinit() invokes again by decrements n value once.
3. step 2 continuous execution until n value becomes 0, then line 6, if condition is false. so in line 9, SYSO prints 0.
4. Then, unable to understood that, how the control again goes from line 10 to 5 ??

Answer 1

In this program printit() invoked three times.

how the control again goes from line 10 to 5 ??

Here is how the control flows:

• printit(0) -- n=0, prints "0,", returns 0
• printit(1) -- n=1, prints "0,", returns 0
• printit(2) -- n=2, prints "1,", returns 1
• main()

So Output is: 0,0,1, To understand better put a breakpoint in return statement while debuging.

Here is control/memory flow diagram:

EDIT 1: Alternatively below image explains: