That is the real code I wrote.
Like I said, the guide I've been using didn't have any examples on using JSlider, so I took what it did have on JButtons and tried applying it to JSlider. I've only been at Java for a few weeks.
I don't understand whate you mean by
Classes that extend ChangeListener instead of implementing it, then implementing the wrong method...
Which classes? Could you give me an example of how it should look and why it is supposed to be written that way, please.
Thanks.