Variable scope and lifetime: Correct Solution

Given the following code:

public class Nosghas {
    private int e = 0;
    private static int wo = 0;

    public void otsess(int lomu) {
        int or = 0;
        A
        e += lomu;
        or += lomu;
        wo += lomu;
        System.out.println("e=" + e + "  or=" + or + "  wo=" + wo);
    }

    public static void main(String[] args) {
        Nosghas n0 = new Nosghas();
        B
        Nosghas n1 = new Nosghas();
        C
        n0.otsess(1);
        n1 = n0;
        n1.otsess(10);
        n0.otsess(100);
        n0 = new Nosghas();
        n1.otsess(1000);
    }
}
  1. What does the main method print?
  2. Which of the variables [wo, e, or, n0, n1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    wo=1  e=1  or=1
wo=11  e=10  or=11
wo=111  e=100  or=111
wo=1111  e=1000  or=1111

  2. In scope at A : or, wo, e

  3. In scope at B : or, n0, n1

  4. In scope at C : or, n0, n1

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

  1. or is a static variable, wo is an instance variable, and e is a local variable.

  2. At A , n0 and n1 out of scope because they are local to the main method.

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

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

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