import java.util.*;

class HashMapDemo {

public static void main(String args[]) {

// Create a hash map

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

// Put elements to the map

hm.put("John Doe", 3434.34);

hm.put("Tom Smith", 123.22);

hm.put("Jane Baker", 1378.00);

hm.put("Todd Hall", 99.22);

hm.put("Ralph Smith", -19.08);

// Get a set of the entries

System.out.println(hm);

System.out.println("Bollean value " + hm.containsKey("John Doe"));

Set set = hm.entrySet();

System.out.println(set.isEmpty());

// Get an iterator

Iterator i = set.iterator();

// Display elements

System.out.println(set);

while (i.hasNext()) {

Map.Entry me = (Map.Entry) i.next();

System.out.print(me.getKey() + ": ");

System.out.println(me.getValue());

}

System.out.println();

// Deposit 1000 into John Doe's account

double balance = ((Double) hm.get("John Doe")).doubleValue();

hm.put("John Doe", new Double(balance + 1000));

System.out.println("John Doe's new balance: " + hm.get("John Doe"));

}

}