14. Comparable Clock
Example implementing Comparable for a clock class with hours and minutes.
A Clock class has hours and minutes, two times are compared by first
comparing the hours. If the hours are the same, then compare the minutes.
Write a complete class definition including a constructor and the
compareTo method.
Demo Test Code
public void testCmp() {
Clock a = new Clock(7,30);
Clock b = new Clock(9,25);
int r1 = a.compareTo(b);
System.out.println(r1); // should be negative
Clock c = new Clock(7,21);
int r2 = a.compareTo(c);
System.out.println(r2); // should be positive
}
Solution
public class Clock implements Comparable<Clock> {
private int hour, min;
public Clock(int h, int m) {
hour = h; min = m;
}
public int compareTo (Clock other) {
int answer;
answer = this.hour - other.hour;
if (answer != 0) return answer;
answer = this.minute - other.minute;
return answer;
}
}