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Java HashMap containsKey() Method

❮ HashMap Methods

Example

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

The containsKey() method returns true if an entry with the specified key exists in the map and false otherwise.

Syntax

public boolean containsKey(Object
key )

Parameter Values

ParameterDescription
keyRequired. The key to search for.

Technical Details

Returns:true if an entry with the specified key exists in the map, false otherwise.

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Java HashMap containsValue() Method