Variable scope and lifetime: Correct Solution

Given the following code:

public class Hanho {
    public void ciind(int te) {
        int ac = 0;
        ac += te;
        wesh += te;
        frod += te;
        System.out.println("ac=" + ac + "  wesh=" + wesh + "  frod=" + frod);
        A
    }

    public static void main(String[] args) {
        B
        Hanho h0 = new Hanho();
        Hanho h1 = new Hanho();
        h0.ciind(1);
        h1 = h0;
        h1.ciind(10);
        h0 = h1;
        h0.ciind(100);
        h1.ciind(1000);
        C
    }

    private int wesh = 0;
    private static int frod = 0;
}
  1. What does the main method print?
  2. Which of the variables [frod, ac, wesh, h0, h1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    frod=1  ac=1  wesh=1
frod=10  ac=11  wesh=11
frod=100  ac=111  wesh=111
frod=1000  ac=1111  wesh=1111

  2. In scope at A : wesh, ac

  3. In scope at B : wesh, h0

  4. In scope at C : wesh

Explanation (which you do not need to write out in your submitted solution):

  1. wesh is a static variable, ac is an instance variable, and frod is a local variable.

  2. At A , frod is out of scope because it is not declared yet. h0 and h1 out of scope because they are local to the main method.

  3. At B , h1 is out of scope because it is not declared yet. ac is out of scope because it is an instance variable, but main is a static method. frod is out of scope because it is local to ciind.

  4. At C , h0 and h1 are out of scope because they are not declared yet. ac is out of scope because it is an instance variable, but main is a static method. frod is out of scope because it is local to ciind.

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