Reference Modification With OF

COBOL Reference Modification With OF
Syntax to use reference modification for a filed, which exists in multiple groups.
Ex:

01 ww-grp1
   03 name1 pic x(10)
   03 sal pic 9(4)

01 ww-grp2
   03 name1 pic x(10)
   03 sal pic 9(4)

name1 exists in both groups. So if we want to use reference modification for ww-grp1

move name1 of ww-grp1(1:4) to var1

move name1(1:4) of ww-grp1 to WW-var1

Above one will not work as it is not correct syntactically.

Basic details of Ref. Modification:

This is used to move a partial value from one variable in to another variable. For example if in a variable declared as a FULL-Name in which first 10 characters are of First-Name and last 10 characters are of Last-Name, then if only first name needs to be moved into another field. it can be done using ref. modification without changing the declaration of the field.

MOVE FUL-NAM(1:10) TO FRST-NAM
MOVE FUL-NAM(10:10) TO LST-NAM

2nd statement can also be coded like

MOVE FUL-NAM(10:) TO LAST-NAM.

In this case starting from 10th position remaining part would be moved to destination.

For more details and syntax go thru the official IBM pages @

IBM Reference