Question

I called: example3(2);

public static void example3(int n){
if(n>0){
example3(n-1);
}
System.out.print(n + " ");
}



I know the output is 0 1 2.
I don't know why the 2 is outputted though. First thing that happens is example3(2-1), which is 1. Then example3(1-1), which is 0.
But where does the 2 come from?

Answer 1

You have the following function defined:

public static void example3(int n)
{
if (n > 0)
example3(n - 1);
System.out.print(n + " ");
}

If you call example3(2), this is what happens:

1. example3(1) is called.
2. example3(0) is called.
3. 0 is displayed and we return to step 2.
4. 1 is displayed and we return to step 1.
5. 2 is displayed and the program terminates.

Answer 2

Remember that this is not a tail-recursive function, and as a result, things still happen even after the base case is reached.

Answer 3

Thank you!