public class StringComparison {

    public static class Point {
        public int x, y;
    }

    public static void main(String[] args) {

        /* Difference between value and reference */

        int a1 = 1;
        int a2 = a1;
        a1 = 2;
        System.out.println(a1 + " " + a2);

        Point p1 = new Point();
        p1.x = 1;
        Point p2 = p1;
        p1.x = 2;
        System.out.println(p1.x + " " + p2.x);

        /* String comparison and interned strings */
        String s1 = "ab";
        String s2 = "ab";
        String s3 = "abc".substring(0, 2);

        System.out.println(s1);
        System.out.println(s2);
        System.out.println(s3);

        System.out.println(s1 == s2);
        System.out.println(s2 == s3);
        System.out.println(s2.equals(s3));

        /* Additional string comparisons */

        System.out.println(s1.startsWith(s2));
        System.out.println(s2.contains(s3));
    }

}