Confusion in line

[JavaJunkie]

Hi,

I've little confusion in the line of page no. 552 of HeadFirst Java, that says:

The other option (if it's possible) would be to subclass the element and make the subclass implement Comparable.

What does "subclass the element" mean in above line?

Thanks in advance.

[Fubarable]

Create a child class from the element's class. Say the original class is called Element, then create something like so:

public class Child extends Element implements Comparable<Child> {
  
}

Note that I do not have this book, so a better answer may require more context.