How to create HashMap in Java?

package com.kt4study.corejava.collection; import java.util.HashMap; /**  * @author kt4study.blogspot.co.uk  *   */ public class HashMapExample {   public static HashMap<String, Integer> getHashMap() {     // Create An Instance Of HashMap     HashMap<String, Integer> hashMap = new HashMap<String, Integer>();     // Add String as Key and Integer as Value in HashMap.     hashMap.put("No Of Players In Football", 11);     hashMap.put("No Of Players In Chess", 1);     hashMap.put("No Of Players In Volleyball", 6);     hashMap.put(null, 20);     return hashMap;   }   public static void main(String[] args) {     HashMap<String, Integer> hashMap = HashMapExample.getHashMap();     // Print all the elements From HashMap     for (String key : hashMap.keySet()) {       System.out.println("Element from HashMap:: " + key + " - " + hashMap.get(key));     }   } }

Output → HashMap can have "null" key and "null" value. All keys are unique in HashMap.

Element from HashMap:: null - 20
Element from HashMap:: No Of Players In Volleyball - 6
Element from HashMap:: No Of Players In Football - 11
Element from HashMap:: No Of Players In Chess - 1