¥The interface Comparable is built-in
to Java (part of the core library java.lang) has the following definition
¥ interface Comparable {
int
compareTo(Object other);
}
The value returned by compareTo is negative, zero, or positive depending on
whether this is less than other, equal to other, or greater than other.
¥The built-in class String also
implements the interface CharSequence which includes methods such as int length(). The built-in class StringBuffer
(mutable strings) also implements
this interface.