When I came across the following example I did not expect the results that the program has printed hehe…

Question: What does this program print? Why?

import java.util.*;

public class SetList {

    public static void main(String[] args) {

    Set<Integer> set =
    			new TreeSet<Integer>();
    List<Integer> list =
    			new ArrayList<Integer>();

    for (int i = -3; i < 3; i++) {
        set.add(i);
        list.add(i);
    }

    for (int i = 0; i < 3; i++) {
        set.remove(i);
        list.remove(i);
    }

     System.out.println(set + " " + list);
   }
}

Looking forward for your answers dear readers

Resources:
Effective Java