RE: Testing for valid numeric in an alpha field

--- "Stone, Joel" <StoneJ@xxxxxxxxxxxxxxxx> wrote:
> Actually I think your RPG test is not reliable.  I think that TESTN will let
> certain non-numerics slip through, only to explode sometime later (probably
> in the middle of the night)!
> 
> In RPG it is much safer to use '0123456789' CHECK  variable_name to ensure
> numerics.
> 
> In COBOL, if you only want to test the first part of a field, try
> 
> If VNCOMPANY (1:4) is numeric
>    move VNCOMPANY to ws-vnd-company
> else
>    move zeros     to ws-vnd-company
> end-if. 

Thanks Joel.  The idea behind TESTN is that you have a value in an alpha field 
that can be safely
moved into a numeric field without triggering a DDE.  Once TESTN blesses the 
value and it is moved
into the numeric field, that's when we would test for negative values.  But I 
like your idea using
the CHECK, I'll tuck that one away for next time.

Your example using the "end-if".  Is that essentially a no-op?  Does it provide 
any more function
than if you'd just put the period at the end of the previous statement?  One of 
the things I'm
still trying to get comfortable with in Cobol is the idea that you can have 
multiple IF's in one
statement.  (As opposed to RPG, every IF has its own ENDIF.)  What about nested 
IF's?  Does Cobol
support that?  (My brief exposure to Cobol 20 years ago left me with the 
impression that the way
to accomplish that is to break it up into more sub-procedures.)

TIA, Dan

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