Do NOT do that! setNum(num);//fix- until someone fixes your setter. Your getter should not call your setter with the uninitialized value of
num(e.g.
0`).
I suggest making a few small changes -
public static class Vars { private int num = 5; // Default to 5. public void setNum(int x) { this.num = x; // actually "set" the value. } public int getNum() { return num; } }