Recursion with Return instruction without parameter

Question

Please I have a doubt about following code:
public void solveTowers( int disks, int sourcePeg, int destinationPeg,
int tempPeg )
if ( disks == 1 )
System.out.printf( "\n%d --> %d", sourcePeg, destinationPeg );
return;
solveTowers( disks - 1, sourcePeg, tempPeg, destinationPeg );
System.out.printf( "\n%d --> %d", sourcePeg, destinationPeg );
If I enter witch amount variable DISK = 3
I'd like to known: Why ouput after perform the code is
1--->3
2--->3
1--->3 ?
I didn't get it about the mechanism logical of RETURN instruction !!!
Please, some could me help and explain about with mechanism
OBS: An draw or design it will be helpfull for me understant
A lot of thanks
Gmourad

Answer 1

You didn't mention other parameters of your recursive method, so I am not guessing but here is an easier example.
public class Test{
     public void resursive(int num) {
          if (num == 1) {
               System.out.println(num);
               return;
          resursive(--num);
          System.out.println(num);
    public static void main(String[] args) {
          int num = 3;
          Test myTest = new Test();
          a.resursive(num);
1
1
2
recursive(3) -> recursive(2)                                          // print 2
                recursive(2) -> recursive(1)              // print 1
                                recursive(1) -> // print 1It would print the last one first because the upper one would call itself first before print out the value.