Thread: Exception at main...

The length of your Object array = 2;
The element you're trying to access using 'options[3]' = 4.

You can't use what doesn't exist.

 Object[] options = {"Integers", "Doubles"};
        int in = JOptionPane.showOptionDialog(null, "What sort of multiplying will you be doing?",
                "Calculator Version 3",
                JOptionPane.YES_NO_CANCEL_OPTION,
                JOptionPane.PLAIN_MESSAGE,
                null,
                options,
                options[3]);

In future, post all code here using code tags, and ask proper questions.

Yeah. Saying how new to Java you are and then ending with "here's what I have" is very lazy.
If this was a more complicated issue no one would have a clue what you were on about.

Next time, detail the problems you're receiving, what you were doing when you received the problem and all the error codes with the code which the errors were referring to.
Additionally, always post the code on these forums, but only the relevant ones, we don't want to have to read through lines and lines of code which is of little importance.

! Also; when you post here in the future, don't remove your code once you've been helped. It goes against the community spirit as well as diminishing the chances for other people with a similar issue to resolve their problems without the need of creating additional threads.