Example of keySet method of HashMap.

HashMapKeySet.java

package net.roseindia.java;

import java.util.HashMap;

import java.util.Set;

public class HashMapKeySet {

public static void main(String[] arr) {

/* Create object of HashMap */

HashMap obHashMap = new HashMap();

/* Strore value in HashMap */

obHashMap.put(new Integer(1), "AAA");

obHashMap.put(new Integer(2), "BBB");

obHashMap.put(new Integer(3), "CCC");

obHashMap.put(new Integer(4), "DDD");

obHashMap.put(new Integer(5), "EEE");

/* Create a set of keys of hashmap */

Set obKeySet = obHashMap.keySet();

System.out.println("Set of Keys : " + obKeySet); } }