On Jul 11, 1:11   宮
> Therefore your code should be:
>
>   > testvar = ['cool', 'array']
> testvar = yield testvar
> print testvar
>  
>
> myblock do |stuff|
> return "dumb string"
> end

I was going to post a response similar to yours but you beat me to it.
However, I tried your version, and the return statement is causing an
error. You instead just want to do:

myblock do |stuff|
  "dumb string"
end