Initializing variable using redefines clause in COBOL

[startup]

Please, can anyone help with this beginner's question:

01...
03 v_parameter_1.
05 v_archive_numb pic 9(4).
03 v_archive_char redefines v_parameter_1.
05 filler pic x(4).

When moving spaces to v_archive_char, the v_archive_numb is initialized to 00. This happens even using the Initialize verb.
How can v_archive_numb be initialized to be null.

 

[Crox]

Hi,

I don't understand the example, because when you move space to v-archive-char, the v-archive-num is not numeric anymore, so why would it be zero? On the mainframe the use of this numeric field without the right value will cause a dump.

If you mean x'00' / low-values by null, than you can move low-values to v-parameter-1. But why would you want to do this?

Does this answers your question?

 

[kfmason]

I agree with 'Croxie'. Furthermore, why are you redefining? I can see no benefit. The 03 level (v_parameter_1) will give you alphanumeric access to your 05 level numeric(v_archive_num). Furthermore, I always retain an element of the original field in the redefinition name (eg v_parameter_1_red instead of v_archive_char). It will help whoever has to read your code after you've been knocked down by a bus

 

[BettyScherber]

You don't mention what COBOL you're on, but I'm sure it's a factor. Some COBOLs, including many PC COBOLs, think they are doing you a favor and treat a numeric PIC item as if it had zeros in it when it actually has a value of spaces. Thus any reference to V_ARCHIVE_CHAR after the MOVE would yield SPACES, but a reference to V_ARCHIVE_NUMB would yield ZEROS. If you want to see the SPACES in such a COBOL, you have to refer to the V_ARCHIVE_CHAR field. If you just want the field to be blank in a print line, you might try adding the BLANK WHEN ZERO clause after the PIC clause and then move ZEROS to the field, or just use a PIC Z(4), if zero suppressing everything is acceptable. Betty Scherber
Brainbench MVP for COBOL II

http://www.brainbench.com

 

[RonaldB]

Startup,

to add to kfmason's reaction, your definition could look something like this:

01 ...
03 v_parameter_1.
05 v_archive_numb pic 9(4).

v_archive_numb implicitly redefines v_parameter_1, which is alpanumeric by definition.
If you do need to redefine it explicitly (it happens ...), do it directly:

01 ...
03 v_parameter_1 pic x(4).
03 v_archive_numb pic 9(4) redefines v_parameter_1.

This might not solve your initialisation problems, as BettyScherber pointed out, but at least it's simple and legible.

Good luck !