HashMap example in Java

import java.util.*; 
class HashMapDemo { 
public static void main(String args[]) { 
// Create a hash map 
HashMap hm = new HashMap(); 
// Put elements to the map 
hm.put("John Doe", new Double(3434.34)); 
hm.put("Tom Smith", new Double(123.22)); 
hm.put("Jane Baker", new Double(1378.00)); 
hm.put("Todd Hall", new Double(99.22)); 
hm.put("Ralph Smith", new Double(-19.08)); 
// Get a set of the entries 
Set set = hm.entrySet(); 
// Get an iterator 
Iterator i = set.iterator(); 
// Display elements 
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")); 
} 
}