MyClass.java
 

import java.util.HashMap;

public class MyClass {
  public static void main(String[] args) {
    HashMap capitalCities = new HashMap();
    capitalCities.put("England", "London");
    capitalCities.put("Germany", "Berlin");
    capitalCities.put("Norway", "Oslo");
    capitalCities.put("USA", "Washington DC");
    capitalCities.clear();
    System.out.println(capitalCities); 
  }
}

Result:
{}