Java OCA OCP Practice Question 3229

public enum Main {
  PLATINUM(20), GOLD(10), SILVER(5), BASIC(0);
  private double extra;

  Main(double extra) {
    this.extra = extra;
  }//from w  ww .j av a 2 s  .  co m

  public static void main (String[] args) {
    System.out.println(GOLD.ordinal() > SILVER.ordinal());
    System.out.println(max(GOLD,SILVER));
    System.out.println(max2(GOLD,SILVER));
  }

  public static Main max(Main c1, Main c2) {
    Main maxFlyer = c1;
    if (c1.compareTo(c2) < 0)
      maxFlyer = c2;
    return maxFlyer;
  }

  public static Main max2(Main c1, Main c2) {
    Main maxFlyer = c1;
    if (c1.extra < c2.extra)
      maxFlyer = c2;
    return maxFlyer;
  }
}

(a)  The program will compile and print:

    false//ww w .  jav a2s. c  o m
     SILVER
    GOLD

(b)  The program will compile and print:

    true
    GOLD
     SILVER

(c)  The program will compile and print:

    true
    GOLD
    GOLD

(d)  The  program  will  not  compile,  since  the  enum  type  Main  does  not
    implement the Comparable interface.