[Jprogramming] How to tell if all boxes in a row are empty?

[robert therriault]

Based on using a: as the empty value.
 
   [ a1=: 6#a:
┌┬┬┬┬┬┐
│││││││
└┴┴┴┴┴┘
   [ a2=: a1,(<'b'),a1
┌┬┬┬┬┬┬─┬┬┬┬┬┬┐
│││││││b│││││││
└┴┴┴┴┴┴─┴┴┴┴┴┴┘
  ([: */ a:= ])  a1
1
   ([: */ a:= ])  a2
0

   NB. or in explicit, since you don't like tacit

   */ a:= a1
1
   */ a:= a2
0
   
Cheers, bob

> On May 31, 2016, at 10:02 PM, PR PackRat <hhpackrat at gmail.com> wrote:
> 
> I need to perform a certain action if an entire row in a transposed
> table (i.e., originally a column) has empty values, that is, all boxed
> data are the equivalent of a: or ''.  The result should be a Boolean
> value--"true" meaning that the entire row has empty values.  (A
> typical application would be old stock market data, where all of the
> "Open" values might be null or empty.)
> 
> I don't know how to even begin writing such code (without a for/next
> loop to separately evaluate each box's value, a very non-J way of
> doing it).  Please help.  Thanks in advance!
> 
> 
> Harvey
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