Use the keySet() method if you only want the keys
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");
for (String i : capitalCities.keySet()) {
System.out.println(i);
}
}
}
//USA (key)
//Norway (key)
//England (key)
//Germany (key)