import java.util.Hashtable;
public class Main {
public static void main(String[] args) {
Hashtable ht = new Hashtable();
ht.put("1", "One");
ht.put("2", "Two");
ht.put("3", "Three");
boolean blnExists = ht.containsKey("2");
System.out.println("2 exists in Hashtable ? : " + blnExists);
}
}