COBOL Coding chronicles: Strategies for error free MOVEment of values to destination data-item.

🚀 Just encountered and solved a common issue in COBOL programming! 💻

Today, while working on a COBOL program, I faced an issue where an improper value was being moved to a `COMP-3` data item defined as,

 05 WS-COMP-DATA-ITEM PIC S9(7) COMP-3 VALUE 0.  

The MOVE statement looked like below,

 MOVE WS-GROUP-DATA-ITEM TO WS-COMP-DATA-ITEM.  

After some debugging, I found that the source data item, a group level data item (WS-GROUP-DATA-ITEM) was type less, meaning it was neither numeric nor alphanumeric.

This is how the group data item was defined,

 05 WS-GROUP-DATA-ITEM.  
    10 WS-VAR1 PIC 9(2) VALUE 0.  
    10 WS-VAR2 PIC 9(2) VALUE 0.   

To fix the issue, I redefined the group level data item as follows:

 05 WS-GROUP-DATA-ITEM.  
    10 WS-VAR1 PIC 9(2) VALUE 0.  
    10 WS-VAR2 PIC 9(2) VALUE 0.   
 05 WS-GROUP-DATA-ITEM-N REDEFINES WS-GROUP-DATA-ITEM PIC 9(4).  

Then, I referenced the newly defined data item WS-GROUP-DATA-ITEM-N in the MOVE statement:

 MOVE WS-GROUP-DATA-ITEM-N TO WS-COMP-DATA-ITEM.  

Voila! The issue was resolved, and the data was correctly moved to the COMP-3 field.

To better understand the issue, take a look at the following code snippets.

• Code snippet that moves junk values to the COMP-3 field.
• Corrected version of the code with REDEFINES clause.

Lessons learned: Proper data representation is key in COBOL programming, and addressing type less data items through redefinition can be the solution to tricky issues.

Hope this helps!