Variable scope and lifetime: Correct Solution

Given the following code:

public class Girho {
    public static void main(String[] args) {
        A
        Girho g0 = new Girho();
        Girho g1 = new Girho();
        B
        g0.seunt(1);
        g1 = new Girho();
        g0 = g1;
        g1.seunt(10);
        g0.seunt(100);
        g1.seunt(1000);
    }

    private static int ca = 0;
    private int beo = 0;

    public void seunt(int crau) {
        int wi = 0;
        beo += crau;
        wi += crau;
        ca += crau;
        System.out.println("beo=" + beo + "  wi=" + wi + "  ca=" + ca);
        C
    }
}
  1. What does the main method print?
  2. Which of the variables [ca, beo, wi, g0, g1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    ca=1  beo=1  wi=1
ca=10  beo=10  wi=11
ca=110  beo=100  wi=111
ca=1110  beo=1000  wi=1111

  2. In scope at A : wi, g0

  3. In scope at B : wi, g0, g1

  4. In scope at C : wi, ca

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

  1. wi is a static variable, ca is an instance variable, and beo is a local variable.

  2. At A , g1 is out of scope because it is not declared yet. ca is out of scope because it is an instance variable, but main is a static method. beo is out of scope because it is local to seunt.

  3. At B , ca is out of scope because it is an instance variable, but main is a static method. beo is out of scope because it is local to seunt.

  4. At C , beo is out of scope because it is not declared yet. g0 and g1 out of scope because they are local to the main method.

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