Map.Entry

Map.Entry: interface enables you to work with a map entry.
The entrySet( ) method declared by the Map interface returns a Set containing the map entries. Each of these set elements is a Map.Entry object.
Following table summarizes the methods declared by this interface.

SN	Methods with Description
1	boolean equals(Object obj) Returns true if obj is a Map.Entry whose key and value are equal to that of the invoking object.
2	Object getKey( ) Returns the key for this map entry.
3	Object getValue( ) Returns the value for this map entry.
4	int hashCode( ) Returns the hash code for this map entry.
5	Object setValue(Object v) Sets the value for this map entry to v. A ClassCastException is thrown if v is not the correct type for the map. A NullPointerException is thrown if v is null and the map does not permit null keys. An UnsupportedOperationException is thrown if the map cannot be changed.

Example:

Following is the example showing how Map.Entry can be used:

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("Zara", new Double(3434.34)); hm.put("Mahnaz", new Double(123.22)); hm.put("Ayan", new Double(1378.00)); hm.put("Daisy", new Double(99.22)); hm.put("Qadir", 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 Zara's account double balance = ((Double)hm.get("Zara")).doubleValue(); hm.put("Zara", new Double(balance + 1000)); System.out.println("Zara's new balance: " + hm.get("Zara")); } }

This would produce following result:

Daisy 99.22 Qadir: -19.08 Zara: 3434.34 Ayan: 1378.0 Mahnaz: 123.22 Zara.s current balance: 4434.34