Java Program to retrieve the set of all keys in HashMap

First, create a HashMap and add elements

HashMap hm = new HashMap(); hm.put("Wallet", new Integer(700)); hm.put("Belt", new Integer(600)); hm.put("Backpack", new Integer(1200));

Now, retrieve all the keys

Set keys = hm.keySet(); System.out.println("\nKeys..."); Iterator i = keys.iterator(); while (i.hasNext()) {    System.out.println(i.next()); }

The following is an example to get the set of all key in HashMap

Example

 Live Demo

import java.util.*; public class Demo { public static void main(String args[]) { // Create hash map HashMap hm = new HashMap(); hm.put("Wallet", new Integer(700)); hm.put("Belt", new Integer(600)); hm.put("Backpack", new Integer(1200)); System.out.println("Map = "+hm); Set keys = hm.keySet(); System.out.println("\nKeys..."); Iterator i = keys.iterator(); while (i.hasNext()) { System.out.println(i.next()); } } }

The following is the output

Map = {Backpack=1200, Belt=600, Wallet=700} Keys... Backpack Belt Wallet