uses a generic Hashtable to store the names of bank depositors and their current balances : Hashtable Basics « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. Hashtable Basics

import java.util.Enumeration;
import java.util.Hashtable;

class HTDemo {
  public static void main(String args[]) {
    Hashtable<String, Double> balance = new Hashtable<String, Double>();

    Enumeration<String> names;
    String str;
    double bal;

    balance.put("A", 3434.34);
    balance.put("B", 123.22);
    balance.put("C", 1378.00);
    balance.put("D", 99.22);
    balance.put("E", -19.08);

    names = balance.keys();
    while (names.hasMoreElements()) {
      str = names.nextElement();
      System.out.println(str + ": " + balance.get(str));
    }
    bal = balance.get("A");
    balance.put("A", bal + 1000);
    System.out.println("A's new balance: " + balance.get("A"));
  }
}