understanding basic recursion

Question

public static void main (String[] args)
{
    System.out.println(factorial(5));
}

public int factorial(int n)
{
    if(n <= 1){
        return 1;
    }
    else{         


        

Answer 1

1. In the initial call to factorial, n=5, and is pushed on the stack.
2. Then the else is triggered so 4 is passed to factorial, and is also pushed onto the stack.
3. Then the else is triggered so 3 is passed to factorial, and is also pushed onto the stack.
4. Then the else is triggered so 2 is passed to factorial, and is also pushed onto the stack.
5. Then the else is triggered so 1 is passed to factorial, and is also pushed onto the stack.
6. Then the else is triggered so 0 is passed to factorial, and is also pushed onto the stack.
7. The if gets triggered and 1 is returned to the calling factorial.
8. The if gets triggered and 2 * 1 is returned to the calling factorial.
9. The if gets triggered and 3 * 2 is returned to the calling factorial.
10. The if gets triggered and 4 * 3 is returned to the calling factorial.
11. The if gets triggered and 5 * 4 is returned to the calling factorial.

The stack also gets cleaned up, however that gets too tedious to type. Essentially all values in a method call are pushed onto the stack, and popped off the stack on the methods return. This keeps them separated between recursive calls.