Variable scope and lifetime: Correct Solution

Given the following code:

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

    private static int pece = 0;
    private int ic = 0;

    public void hecSelo(int aboc) {
        C
        int ili = 0;
        ili += aboc;
        pece += aboc;
        ic += aboc;
        System.out.println("ili=" + ili + "  pece=" + pece + "  ic=" + ic);
    }
}
  1. What does the main method print?
  2. Which of the variables [ic, ili, pece, l0, l1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    ic=1  ili=1  pece=1
ic=10  ili=11  pece=10
ic=100  ili=111  pece=100
ic=1000  ili=1111  pece=1000

  2. In scope at A : ili, l0

  3. In scope at B : ili, l0, l1

  4. In scope at C : ili, pece, ic

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

  1. ili is a static variable, pece is an instance variable, and ic is a local variable.

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

  3. At B , pece is out of scope because it is an instance variable, but main is a static method. ic is out of scope because it is local to hecSelo.

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

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