Variable scope and lifetime: Correct Solution

Given the following code:

public class Shas {
    private int on = 0;
    private static int toim = 0;

    public void eiaNuprer(int taf) {
        A
        int te = 0;
        on += taf;
        toim += taf;
        te += taf;
        System.out.println("on=" + on + "  toim=" + toim + "  te=" + te);
    }

    public static void main(String[] args) {
        B
        Shas s0 = new Shas();
        Shas s1 = new Shas();
        C
        s0.eiaNuprer(1);
        s1.eiaNuprer(10);
        s0 = new Shas();
        s0.eiaNuprer(100);
        s1 = new Shas();
        s1.eiaNuprer(1000);
    }
}
  1. What does the main method print?
  2. Which of the variables [te, on, toim, s0, s1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    te=1  on=1  toim=1
te=10  on=11  toim=10
te=100  on=111  toim=100
te=1000  on=1111  toim=1000

  2. In scope at A : on, te, toim

  3. In scope at B : on, s0

  4. In scope at C : on, s0, s1

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

  1. on is a static variable, te is an instance variable, and toim is a local variable.

  2. At A , s0 and s1 out of scope because they are local to the main method.

  3. At B , s1 is out of scope because it is not declared yet. te is out of scope because it is an instance variable, but main is a static method. toim is out of scope because it is local to eiaNuprer.

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

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