What code? Do you mean the code of the original posting of Empty string checking in output? If so, there is definitely a mistake as explained by toolic in Re: Empty string checking in output: the value of the  @output array evaluated in scalar context (imposed by the comparison operator) and then stringified (for the string comparator) will never be anything other than a string like '0', '1', '2', etc., and so will never be anything other than not-equal to the empty string, and so the false clause of the conditional will never execute.