java retain information in recursive function

Question

Is it possible to retain information via a helper function with java, without using static variables.

For example,

public void foo(){
    int v = 0;
         


        

Answer 1

Why not make it an instance variable(not necessarily static)...??

public class Recursive {
    int v = 0;
    public void foo(){

        fooHelper(2);
        System.out.println(v);
    }

    public void fooHelper(int depth){
        v++;
        if(depth-1!=0)//Added this because I was getting an StackOverflowError
        fooHelper(depth-1);
    }

    public static void main(String[] args) {
        Recursive r = new Recursive();
        r.foo();
    }
}

Answer 2

Because the variable v is of primitive type, changes made to it will not be visible outside the function scope. You could declare the variable v inside a class, say State and pass the state object into the recursive function to get the required effect.

public void foo(){
    State state = new State();
    fooHelper(state, 2);
}

public void fooHelper(State state, int depth){
    state.v++;
    fooHelper(state, depth-1);
}

class State {
    int v;
}

Hope it helps.