positive
compareTo()
With all objects, compareTo()
works
the way number comparisons work in ordinary arithmetic.
Here are a few rules.
Most of these are fairly clear if you think about numbers.
Say that A
, B
, and C
are
Integer
s.
If A.compareTo(B) > 0
then B.compareTo(A) < 0
.
If A.compareTo(B) > 0
and B.compareTo(C) > 0
then A.compareTo(C) > 0
.
If A.compareTo(B) == 0
then A.compareTo(Z)
and B.compareTo(Z)
should give the
same result, no matter what Z is.
The classes that come with Java follow these rules.
If you write a class that implements Comparable
,
you need to follow these rules.
This is not hard to do because
most sensible compareTo()
methods will do this naturally.
Say that X.compareTo(Y)==0
.
Is it then true that X.equals(Y)
?