import java.util.HashMap; import java.util.HashSet; public class HashMapSet{ public static void main(String[] args){ System.out.println("----HashMap----"); HashMap<String,Integer> hashmap_obj = new HashMap<String,Integer>(); hashmap_obj.put("One",1); hashmap_obj.put("Two",2); hashmap_obj.put("Three",3); hashmap_obj.put("Four",4); hashmap_obj.put("Five",5); System.out.println(hashmap_obj); //looping hash map for(String i:hashmap_obj.keySet()){ System.out.println("Key : "+i+", Values : "+hashmap_obj.get(i)); } System.out.println(hashmap_obj.get("One")); //hashmap_obj.set("One",22);//throw error set property not allowed System.out.println("Size : "+hashmap_obj.size()); //Hash set is same as otherss, nothing big different } }