Java HashMapcontainsKey() Method
Example
Check if a key exists in a map:
import java.util.HashMap;public class Main { public static void main(String[] args) { HashMap<String, String> capitalCities = new HashMap<String, String>(); capitalCities.put("England", "London"); capitalCities.put("Germany", "Berlin"); capitalCities.put("Norway", "Oslo"); capitalCities.put("USA", "Washington DC"); System.out.println(capitalCities.containsKey("England")); System.out.println(capitalCities.containsKey("Canada")); }}Definition and Usage
ThecontainsKey() method returnstrue if an entry with the specified key exists in the map andfalse otherwise.
Syntax
public boolean containsKey(Objectkey)Parameter Values
| Parameter | Description |
|---|---|
| key | Required. The key to search for. |
Technical Details
| Returns: | true if an entry with the specified key exists in the map,false otherwise. |
|---|
Related Pages
❮ HashMap Methods
