Question

In the tree class I’m suppose to compare two node, for you know searching and adding items. I have some issues with how to make it comparable. When one adds data(generic, anything) to the tree one calls the Tree class which then makes a new Node object. How can I declare the variable data/element in the Node class so that it is of type E (anything) and still Comparable? Seriously, I’ve tried back and forth without concluding with anything.

Answer 1

Not everything is Comparable. Your requirement is self-contradictory. You can constrain E to be comparable by declaring the generic parameter like:

< E extends Comparable<E> >

This way, the consumer of the class can use all classes that implement Comparable interface with it. You’ll be able to access the compareTo method on things typed E.