Hi Ryan, Thanks for your help. I tried that, and it didn't work. Here is my irb transcript trying that. Is there another way to remove a constant? I thought I had seen one in the Pickaxe book, but maybe I was thinking of the module method. irb irb(main):001:0> FOO = "my symbol value" => "my symbol value" irb(main):002:0> remove_const(FOO) NoMethodError: undefined method `remove_const' for main:Object from (irb):2 irb(main):003:0> remove_const(:FOO) NoMethodError: undefined method `remove_const' for main:Object from (irb):3 irb(main):004:0> ?? Any other ideas? Thanks, Bob Evans On Nov 14, 2005, at 1:44 PM, Ryan Leavengood wrote: > On 11/14/05, Robert Evans <robert.evans / acm.org> wrote: >> >> I expected the unit test to clean the environment, in lieu of that, >> how can I undefined const? > > ---------------------------------------------------- > Module#remove_const > remove_const(sym) => obj > ---------------------------------------------------------------------- > -- > Removes the definition of the given constant, returning that > constant's value. Predefined classes and singleton objects > (such as > _true_) cannot be removed. > > You pass it a symbol: remove_const(:VARIABLE) > > Ryan >