IBM Mainframe Forum

What is the difference between RENAMES and REDEFINES clause? Could you explain with some example. I went through the COBOL Language Reference, but I am not able to get that clearly.

Thanks,
Bala

Hi

renames : regrouping of data elements is nothing but renames
for this we have to use 66 level number
redefines : reusing of storage space is nothing but redefines
for this level number must be same

Here is a REDEFINES example:


Here is a RENAMES example:

Hi,kbmkris
Hope my answer will help you...
REDEFINES:Give a computer storage area MORE THAN ONE names that all point to this area.
Even this data-type of every names can be different.

RENAMES:Regroup some of the Elementary-data-item in a GROUP.It gives this ele-data-item a new name can be operate more convenience.

Correct me ,plz if sth is wrong...thx.

RENAMES lets you give a name to series of items without needing to have a group item above them. For example,


Notice that there is no need to define a group item that includes only dt-month and dt-day, because I can use "thru". For "redefines" you would need a separate group item for those 2 items.

Another advantage of "renames" is that you don't need to specify any pic. It just puts together all the pic's that you are renaming to create a new one for the renamed item. In this example, it automatically comes up with pic 9999 for short-date, without you having to put it in the code.

On the other hand, the disadvantage of "renames" is that you can't change the format at all. That is what "redefines" is for.

hi,
RENAME is nothing but regrouping of data items,it should be given 66 level only
EX.
01 emp-rec
05 emp-name pic x(10).
05 emp-no pic 9(5).
01 emp-sal
05 ta-da pic 9(3).
05 bonus pic 9(3).
66 re-emp renames emp-no thru ta-da.
so re-emp regroups emp-no and ta-da.
REDEFIES:different data items using same memory location.
EX.
01 emp-rec.
05 emp-name pic x(20).
05 ws-emp-rec redefines
10 emp-first-name pic x(5).
10 enp-last-name pic x(5).
in redefines clause redefines variable should follow the first variable.

Rename clause is used for renaming a particular defined variable.
redefing clause is used for redefing the same working storage area by more than one variable
example for rename clause:
01 empno
05 empno1 pic 9(4).
05 empno2 pic 9(4).
01 empname.
05 empname1 pic x(10).
05 empname2 pic x(10).
01 empsalary.
05 empsal1 pic 9(4).
05 empsal2 pic 9(4).
66 empdetails rename empno thru empsalary.
example for redefine clause
01 a pic 9(5)
01 b redefines a pic 9(5) value 10000.
//*here the variable b will take the memory of a
display b.
//*here the output will be 10000.
01 c redefines b pic 9(3) value 100.
display c.
//* here the output will be 100.

now consider we can redefine pic 9(6) by pic 9(8). and we can also redefine pic 9(5) by pic 9(2).
we can also redefine pic 9(3) by pic x(2).

if i am wrong in any of the description i given above am sorry , please correct me.

RENAMES clause will occur only at 66 Level.

Check this REDEFINE and RENAME CLAUSE