"apple", "orange", "plum".
This is the order that compareTo()
would place the strings.
Comparable<T>
Interface
An interface consists of constants and method declarations.
The Comparable<T>
interface consists of just one method (and no constants):
int compareTo( T obj )Compare the object running the method withobj
, which is of type T. Return a negative integer, zero, or a positive integer, when he object running the method is less than, equal, or greater thanobj
.
T
stands for the type of the objects.
If the objects are String
s, then T
is String
.
String
s implement the Comparable<String>
interface.
If an object is of a class that implements Comparable
,
then that object is less than, equal, or greater than
any object of that class.
compareTo()
returns an integer to show which of these three relations hold.
Relation | objectA.compareTo( objectB ) | ||
---|---|---|---|
objectA | Less Than | objectB | Negative Integer |
objectA | Equal | objectB | Zero |
objectA | Greater Than | objectB | Positive Integer |
Does compartTo()
tell us enough?
If any two objects can be compared, and the result is less than, equal, or greater than is this enough to put a collection of objects in order?