Extends a class that implements an interface

[monocole]

I have a class

public class Element implements Comparator{

and another class
public class Block extends Element {

Shouldn't the class Block implements Comparator!?!? I have a lot of extension of Element there is a easy way to implement this in each child of Block?

[sunde887]

The best way to check is by writing a simple tester program that uses the comparator of the sub class. It will either work, or cause an error.

[ozzyman]

When a class extends another class it inherits all public methods and fields, therefore it should work without Block needing to implement the Compare interface as the public method compare(Obj, Obj) will be inherited from your Element class.