Creating a HashMap and iterating its elements

 

import java.util.HashMap;

public class HashMapDemo {

public static void main(String[] args) {

//Creating HashMap;

HashMap<Integer, String> hm = new HashMap<>();

//Putting element

hm.put(1, "Naidu");

hm.put(3, "Rohilla");

hm.put(5, "Vijay");

hm.put(2, "Rahul");

hm.put(4, "Ramakesh");

//adding duplicate Value

//this will replace the element;

//can't store duplicate Values;

hm.put(5, "Sudeep");

//Storing null value

hm.put(null, null);

System.out.println("Iterating HashMap...");

System.out.println(hm);

}

}