HashMap Class in Java Framework

Example: Program to implement methods available in HashMap class

import java.util.*;
public class HashMapDemo
{
      public static void main(String args[])
      {
            //creates HashMap
            HashMap<Integer, String> hm = new HashMap<Integer, String>();
            System.out.println("Initial size of HashMap: "+hm.size());

            //add the element
            hm.put(01, "Black");
            hm.put(10, "White");
            hm.put(11, "Smith");
            hm.put(new Integer(05),"Johns" );
            hm.put(new Integer(40), "Tom");
            Set set = hm.keySet();
            System.out.println("HashMap element after adding:");
            Iterator itr = set.iterator();
            while(itr.hasNext())
            {
                  Object key = itr.next();
                  Object value = hm.get(key);
                  System.out.println(key+": "+value);
            }
            System.out.println("Size of HashMap after add: "+hm.size());
            System.out.println("HashMap is Empty: "+hm.isEmpty());
            System.out.println("HashMap elements after delete:");

            //delete the element
            hm.remove(11);
            Set set1 = hm.keySet();
            Iterator itr1 = set1.iterator();
            while(itr1.hasNext()){
            Object key = itr1.next();
            Object value = hm.get(key);
            System.out.println(key+": "+value);
      }
      System.out.println("Size of HashMap after deletion: "+hm.size());
}