Variable scope and lifetime: Correct Solution

Given the following code:

public class Ogde {
    public static void main(String[] args) {
        Ogde o0 = new Ogde();
        A
        Ogde o1 = new Ogde();
        B
        o0.ociSti(1);
        o1.ociSti(10);
        o1 = new Ogde();
        o0.ociSti(100);
        o0 = new Ogde();
        o1.ociSti(1000);
    }

    public void ociSti(int wi) {
        int pric = 0;
        C
        pric += wi;
        in += wi;
        stri += wi;
        System.out.println("pric=" + pric + "  in=" + in + "  stri=" + stri);
    }

    private int stri = 0;
    private static int in = 0;
}
  1. What does the main method print?
  2. Which of the variables [stri, pric, in, o0, o1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    stri=1  pric=1  in=1
stri=10  pric=11  in=10
stri=100  pric=111  in=101
stri=1000  pric=1111  in=1000

  2. In scope at A : pric, o0, o1

  3. In scope at B : pric, o0, o1

  4. In scope at C : pric, in, stri

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

  1. pric is a static variable, in is an instance variable, and stri is a local variable.

  2. At A , in is out of scope because it is an instance variable, but main is a static method. stri is out of scope because it is local to ociSti.

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

  4. At C , o0 and o1 out of scope because they are local to the main method.

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