Deleting All IDL Main-Level Variables

QUESTION: How can I delete all of my main IDL variables?

ANSWER: Here is a very short program that will do the trick for you.

   PRO DISAPPEAR
   END

When you want to delete all of your main-level IDL variables, type this command:

   IDL> .RNEW Disappear

All of your variables are now gone (or undefined, which is the same thing).

In IDL 5.3, a new executive command was introduced that makes this even easier. Now all you have to do is type this:

   IDL> .Reset_Session