Using Comparable with the core Java classes Many core Java classes and objects implement the Comparable interface, which means we don’t have to implement the compareTo() logic for those classes.

Abstract classes and interfaces in Java serve fundamentally different purposes. Learn the differences between these Java language elements and how to use them in your programs.

Figure A Collections Framework abstract data structures The Collections Framework defines two other interfaces that are used to sort objects: java.util.Comparable and java.util.Comparator.