Method calling itself.. recursive?

Question

public static int m(int i, int j)    
{     
  if ( i > j)    
    return 0;    
  else    
  {
    i++;    
    m(i++, j);
  }
  return i;    
}

I had two questions. 1.) What is returned by out.print(m(3,8)); and 2.) How many times is the method m called? The answers should be 5 and 7 respectively.

When I worked out question 1, I came out with 5 but the way I did it was incorrect because the method was not called 7 times, it was only called twice. The way I did this was I went straight to the else statement since (i > j) was false at the start and method m was called again this time with (4, 8) I figured it was still false so I went back to the line where m is called and the variable i changed to 5 because of the i++ in m(i++, j). After that it would return 5 for the Value of i.

That was obviously wrong so I added some out.prints for the values of i throughout the program to see how the value was changing and it went from 3 to 9 with an out.print(i); at the beginning of method m. An out.print(i); right before return i; showed the values started to go backwards from 10 to 5 and the method was called 7 times. How does this work?

EDIT: After logging it, I was able to come up with some logic to it but I would like someone to clarify that it is correct.

method m is called with 3,8 at the start. After, it calls itself with 4,8 then 5,8....until 9,8 where the if statement becomes true and the method returns 0. It called itself 6 times so it starts go backwards or decrement-ing 6 times so since m(i++, j) is post(the i) then i becomes 10 and 10 is returned, then 9, then 8, then 7, 6, and finally 5. When it returned 10 that was 1, 9 was 2, 8 was 3, 7 was 4, 6 was 5, and 5 was 6. So since it was 6 when i = 5, that was the value that was returned. Is this correct? And if it is, a more in depth explanation would be nice to have.

Answer 1

To better understand what's happening, it might help to refactor the code as such:

public static int m(int i, int j) {
    static int calls = 0;     
    System.out.println("entering.  count: " + calls);
    calls++;

    System.out.println("i = " + i);
    System.out.println("j = " + j);

    if (i > j) { 
        System.out.println("returning 0");
        return 0;
    } else {
        i++;    
        m(i++, j);
    }

    System.out.println("returning " + i);
    return i;    
}

Note that I haven't modified any of the actual logic. All I've done is add some statements to print values, and a variable to keep track of the number of times the method is called.