Variable scope and lifetime: Correct Solution

Given the following code:

public class Brodfa {
    public void medna(int ele) {
        int clal = 0;
        A
        hil += ele;
        clal += ele;
        is += ele;
        System.out.println("hil=" + hil + "  clal=" + clal + "  is=" + is);
    }

    private static int is = 0;
    private int hil = 0;

    public static void main(String[] args) {
        Brodfa b0 = new Brodfa();
        B
        Brodfa b1 = new Brodfa();
        C
        b0.medna(1);
        b1.medna(10);
        b1 = b0;
        b0 = new Brodfa();
        b0.medna(100);
        b1.medna(1000);
    }
}
  1. What does the main method print?
  2. Which of the variables [is, hil, clal, b0, b1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    is=1  hil=1  clal=1
is=10  hil=10  clal=11
is=100  hil=100  clal=111
is=1001  hil=1000  clal=1111

  2. In scope at A : clal, is, hil

  3. In scope at B : clal, b0, b1

  4. In scope at C : clal, b0, b1

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

  1. clal is a static variable, is is an instance variable, and hil is a local variable.

  2. At A , b0 and b1 out of scope because they are local to the main method.

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

  4. At C , is is out of scope because it is an instance variable, but main is a static method. hil is out of scope because it is local to medna.

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