Variable scope and lifetime: Correct Solution

Given the following code:

public class Lollo {
    public static void main(String[] args) {
        A
        Lollo l0 = new Lollo();
        Lollo l1 = new Lollo();
        l0.chies(1);
        l1.chies(10);
        l1 = l0;
        l0.chies(100);
        l0 = new Lollo();
        l1.chies(1000);
        B
    }

    public void chies(int pe) {
        int meku = 0;
        C
        i += pe;
        ti += pe;
        meku += pe;
        System.out.println("i=" + i + "  ti=" + ti + "  meku=" + meku);
    }

    private int ti = 0;
    private static int i = 0;
}
  1. What does the main method print?
  2. Which of the variables [meku, i, ti, l0, l1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    meku=1  i=1  ti=1
meku=11  i=10  ti=10
meku=111  i=101  ti=100
meku=1111  i=1101  ti=1000

  2. In scope at A : meku, l0

  3. In scope at B : meku

  4. In scope at C : meku, i, ti

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

  1. meku is a static variable, i is an instance variable, and ti is a local variable.

  2. At A , l1 is out of scope because it is not declared yet. i is out of scope because it is an instance variable, but main is a static method. ti is out of scope because it is local to chies.

  3. At B , l0 and l1 are out of scope because they are not declared yet. i is out of scope because it is an instance variable, but main is a static method. ti is out of scope because it is local to chies.

  4. At C , l0 and l1 out of scope because they are local to the main method.

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