Variable scope and lifetime: Correct Solution

Given the following code:

public class Voshder {
    private static int mior = 0;

    public static void main(String[] args) {
        A
        Voshder v0 = new Voshder();
        Voshder v1 = new Voshder();
        v0.ocism(1);
        v0 = new Voshder();
        v1.ocism(10);
        v0.ocism(100);
        v1 = v0;
        v1.ocism(1000);
        B
    }

    public void ocism(int di) {
        int hi = 0;
        hi += di;
        pifa += di;
        mior += di;
        System.out.println("hi=" + hi + "  pifa=" + pifa + "  mior=" + mior);
        C
    }

    private int pifa = 0;
}
  1. What does the main method print?
  2. Which of the variables [mior, hi, pifa, v0, v1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    mior=1  hi=1  pifa=1
mior=10  hi=10  pifa=11
mior=100  hi=100  pifa=111
mior=1000  hi=1100  pifa=1111

  2. In scope at A : pifa, v0

  3. In scope at B : pifa

  4. In scope at C : pifa, hi

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

  1. pifa is a static variable, hi is an instance variable, and mior is a local variable.

  2. At A , v1 is out of scope because it is not declared yet. hi is out of scope because it is an instance variable, but main is a static method. mior is out of scope because it is local to ocism.

  3. At B , v0 and v1 are out of scope because they are not declared yet. hi is out of scope because it is an instance variable, but main is a static method. mior is out of scope because it is local to ocism.

  4. At C , mior is out of scope because it is not declared yet. v0 and v1 out of scope because they are local to the main method.

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