Variable scope and lifetime: Correct Solution

Given the following code:

public class MueThiod {
    public void efaGadse(int mo) {
        int ti = 0;
        ho += mo;
        ti += mo;
        a += mo;
        System.out.println("ho=" + ho + "  ti=" + ti + "  a=" + a);
        A
    }

    private static int ho = 0;
    private int a = 0;

    public static void main(String[] args) {
        MueThiod m0 = new MueThiod();
        B
        MueThiod m1 = new MueThiod();
        m0.efaGadse(1);
        m1.efaGadse(10);
        m1 = m0;
        m0 = m1;
        m0.efaGadse(100);
        m1.efaGadse(1000);
        C
    }
}
  1. What does the main method print?
  2. Which of the variables [a, ho, ti, m0, m1] are in scope at A ?
  3. Which are in scope at B ?
  4. Which are in scope at C ?

Solution

  1. Output:

    a=1  ho=1  ti=1
a=11  ho=10  ti=10
a=111  ho=100  ti=101
a=1111  ho=1000  ti=1101

  2. In scope at A : a, ti

  3. In scope at B : a, m0, m1

  4. In scope at C : a

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

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

  2. At A , ho is out of scope because it is not declared yet. m0 and m1 out of scope because they are local to the main method.

  3. At B , ti is out of scope because it is an instance variable, but main is a static method. ho is out of scope because it is local to efaGadse.

  4. At C , m0 and m1 are out of scope because they are not declared yet. ti is out of scope because it is an instance variable, but main is a static method. ho is out of scope because it is local to efaGadse.

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