Variable scope and lifetime: Correct Solution

Given the following code:

public class Naccass {
    private static int siat = 0;
    private int rolt = 0;

    public void shoc(int prur) {
        A
        int elmi = 0;
        siat += prur;
        rolt += prur;
        elmi += prur;
        System.out.println("siat=" + siat + "  rolt=" + rolt + "  elmi=" + elmi);
    }

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

Solution

  1. Output:

    elmi=1  siat=1  rolt=1
elmi=11  siat=10  rolt=10
elmi=111  siat=101  rolt=100
elmi=1111  siat=1000  rolt=1000

  2. In scope at A : elmi, siat, rolt

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

  4. In scope at C : elmi

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

  1. elmi is a static variable, siat is an instance variable, and rolt is a local variable.

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

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

  4. At C , n0 and n1 are out of scope because they are not declared yet. siat is out of scope because it is an instance variable, but main is a static method. rolt is out of scope because it is local to shoc.

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