Java – Check if key exists in HashMap

In Java, you can use the Map.containsKey() method to check if a key exists in a Map.

TestMap.java

package com.mkyong.test;import java.util.HashMap;import java.util.Map;public class TestMap {    public static void main(String[] args) {        Map<String, Integer> fruits = new HashMap<>();        fruits.put("apple", 1);        fruits.put("orange", 2);        fruits.put("banana", 3);        if(fruits.containsKey("apple")){            //key exists            System.out.println(fruits.get("apple"));        }else{            //key not exists        }    }}···Output···1···Alternatively, just check the `null` value like this :###`TestMap.java`

package com.mkyong.test;

import java.util.HashMap;
import java.util.Map;

public class TestMap {

public static void main(String[] args) {    Map<String, Integer> fruits = new HashMap<>();    fruits.put("apple", 1);    fruits.put("orange", 2);    fruits.put("banana", 3);    Integer appleQty = fruits.get("apple");    if(appleQty!=null){        //key exists        System.out.println(appleQty);    }else{        //key not exists    }}

}

Output

1
“`