package com.lokesh.hashset; import java.util.HashSet; import java.util.Set; import java.util.TreeSet; public class HashSetInJava { public static void main(String[] args) { HashSet<Integer> set = new HashSet<>(); set.add(2); set.add(3); boolean b1 = set.add(2); set.add(4); set.add(1); Set<String> st = new HashSet<>(); st.add("c"); st.add("a"); st.add("b"); st.forEach((n)-> System.out.println(n)); set.forEach(System.out::println); System.out.println("See hashset also sort the data automatically\n"); System.out.println(set); System.out.println("b1 = "+b1 + "duplicate value"); System.out.println("\nsize of set" + set.size()); set.remove(1); System.out.println(set); System.out.println(set.isEmpty()); TreeSet<Integer> tset = new TreeSet<Integer>(set); System.out.println(tset+ " This is treeset"); tset.ceiling(2); } }