package set; import java.util.TreeSet; public class TreeSetExample2 { public static void main(String[] args) { TreeSet students = new TreeSet<>(); Student st1 = new Student("John", 2); Student st2 = new Student("Helen", 3); Student st3 = new Student("Gary", 1); Student st4 = new Student("Peter", 4); Student st5 = new Student("Edward", 5); students.add(st1); students.add(st2); students.add(st3); students.add(st4); students.add(st5); System.out.println(students); System.out.println(students.first()); System.out.println(students.last()); Student st6 = new Student("Ron", 2); Student st7 = new Student("Bobby", 4); System.out.println(students.headSet(st6)); System.out.println(students.tailSet(st6)); System.out.println("----------------------"); System.out.println(students.subSet(st6, st7)); System.out.println("----------------------"); System.out.println(st6.equals(st1)); System.out.println(st1.hashCode()); System.out.println(st6.hashCode()); } }