public class ClockDisplay
{
    private NumberDisplay hours;   //private means private to this class(clockdisplay)
    private NumberDisplay minutes;
    private NumberDisplay seconds;
    private String displayString;    // simulates the actual display

    public ClockDisplay() //this is constructor
    {
        hours = new NumberDisplay(13);
        minutes = new NumberDisplay(60);
        seconds = new NumberDisplay(60);
        updateDisplay();
    }

      public ClockDisplay(int hour, int minute, int seconds) // this is constructor
    {
        hours = new NumberDisplay(hour);
        minutes = new NumberDisplay(minute);
        seconds = new NumberDisplay(seconds);
        setTime(hour, minute, seconds);
    }

public void timeTick() // a method
 {
    int hour;

    minutes.increment();
    if(minutes.getValue() == 0) {  // it just rolled over!
    hours.increment();
    hour = hours.getValue() + 1;

    if(hours.getValue() > 12) {

    hour = hours.getValue() - 12;
    hours.setValue(hour);
   }
    }
    {
    updateDisplay();
    }
    }

public void timeTickSeconds()
{
    int minute;

    seconds.increment();
    if(seconds.getValue() == 0) {  // it just rolled over!
    minutes.increment();
    minute = minutes.getValue() + 1;}
    {
    updateDisplay();
    }
}

public void timeMode()
{
           if(hours.getValue() == 0 && minutes.getValue() == 0)
           System.out.println("It is currently Midnight");
           if(hours.getValue() == 12 && minutes.getValue() == 0)
           System.out.println("It is currently Noon");
           if(hours.getValue() > 0) {
           System.out.println("It is currently AM");
           if(hours.getValue() > 12)
           System.out.println("It is currently PM");
           }
}

    public void setTime(int hour, int minute, int second)
    {
        hours.setValue(hour);
        minutes.setValue(minute);
        seconds.setValue(second);
        updateDisplay();
    }

    /**
     * Return the current time of this display in the format HH:MM.
     */
    public String getTime()
    {
        return displayString;
    }

    /**
     * Update the internal string that represents the display.
     */
    private void updateDisplay()
    {
        displayString = hours.getDisplayValue() + ":" + minutes.getDisplayValue() + ":" +
                        seconds.getDisplayValue();
    }


}