import java.util.*; import java.util.HashMap; public class mapimp { public static void main(String[] args) { HashMap map=new HashMap<>(); map.put(0,"jatt"); map.put(1,"jatti"); map.put(2,"ustaad"); map.put(3,"sidhu"); System.out.println(map.get(0)); System.out.println(map.containsKey(4)); } }