A newbie question about : symbol 1

[JebusRocks]

Hello all

I am new to cobol programming(some schooling but little in the way of real world experience) I am looking at a piece of code and need it clarified if you could.

the code is
IF X
MOVE A (1:20) TO B
MOVE A (21:20) TO D
ELSE
DO SOMETHING
END IF

I understand the logic but am wondering about the
(1:20) and (21:20) statements

does
(1:20) mean move 20 characters of A to B starting in position 1
and
(21:20)mean move 20 characters to of A to D starting in position 21
?

Thanks

 

[fredericofonseca]

Yes.

That is called "reference modification", and is a very usefull facility on todays COBOL's.

it is source/destination(start_position:size) where size is optional and if omitted will mean until the end of source/destination.
e.g.
move a to d(10
move b(5 to c

Regards

Frederico Fonseca
SysSoft Integrated Ltd

http://www.syssoft-int.com

 

[JebusRocks]

Thanks for the confirmation fredericofonseca

 

[PHV]

does (1:20) mean move 20 characters of A to B starting in position 1 and (21:20)mean move 20 characters to of A to D starting in position 21
Your guess is right.

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ222-2244

 

[jmanj]

You are absolutely right. In other programming languages this
is called subscripting an example would be:

Let $ABC = Substr($DEF:1,20) where $ABC value will now
becomes the first 20 chars of $DEF.

You could also try if COBOL will replace a character by
using INSPECT whose field is subscripted.
where you inspect a field(n,n) and replace the characters
found.

 

[webrabbit]

jmanj--You mean substringing.

 

[k5tm]

But, since it is not substringing, it would be incorrect to call it that!

Reference modification not only provides the capability to modify the reference to a portion of a data-item, but it also casts the reference to be alphanumeric.

Consider:
[tt]01 my-data pic 999V99.
...
move my-data (1 to something[/tt]


Tom Morrison

http://www.liant.com

 

[webrabbit]

It's not the same as substringing, but it is a lot closer to that thans subscripting.