Practice-It

Suppose that you are provided with a pre-written class ClockTime as described below. Assume that the fields, constructor, and methods shown are implemented. You may refer to them or use them in solving this problem.

// A ClockTime object represents an hour:minute time in  in either standard 
// time such as 10:45 AM or 6:27 PM or military time such as 10:45 hours or
// 18:27 hours.
public class ClockTime {
        private int hour;
        private int minute;
        private String label;

        // Constructs a new time for the given hour/minute.  If time is in
        // standard time, the label is "AM" or "PM".  If the time is in military
        // time, the label is "hours".
        public ClockTime(int h, int m, String label)

        // returns the field values
        public int getHour()
        public int getMinute()
        public String getLabel()

        // returns String for time;
        // example: "06:27 PM"
        // example: "18:27 hours"
        public String toString()

        // your method would go here
}
        

This version of ClockTime can represent times in either standard or military time format. Military time is an alternative way to describe times where hours go from 0 - 24 instead of 1 - 12 (the AM and PM suffixes are not used). The following table shows how to convert between standard and military time:

Write an instance method named toStandardTime that will be placed inside the ClockTime class to become a part of each ClockTime object's behavior. The toStandardTime method converts the ClockTime object into standard time if it is in military time. You can tell which format a particular ClockTime object is using by examining its label field. For example, if the following object is declared in client code:

ClockTime t1 = new ClockTime(15, 27, "hours");
        

The following call to your method would cause 03:27 PM to be printed to the console:

t1.toStandardTime();
System.out.println(t1);    // 03:27 PM 
        

Here are some other objects. Their results when used with your method and then printed to the console are shown at right in comments:

ClockTime t2 = new ClockTime(24, 00, "hours");   // 12:00 AM
ClockTime t3 = new ClockTime( 0, 30, "hours");   // 12:30 AM
ClockTime t4 = new ClockTime(10, 35, "hours");   // 10:35 AM
ClockTime t5 = new ClockTime(12, 15, "hours");   // 12:15 PM
ClockTime t6 = new ClockTime(13, 00, "hours");   // 01:00 PM
ClockTime t7 = new ClockTime(19, 11, "hours");   // 07:11 PM
ClockTime t9 = new ClockTime(23, 59, "hours");   // 11:59 PM
ClockTime ta = new ClockTime( 9, 30, "AM");      // 09:30 AM
ClockTime tb = new ClockTime( 5, 01, "PM");      // 05:01 PM
    

Assume that the state of the ClockTime object is valid and that the label field stores "AM", "PM", or "hours".