Efficient use of decalartion in COBOL

Efficiently use of alphanumeric and numeric declaration in COBOL

In Working Section:

03  WS-ALPHX.                          

    05  WS-NUM          PIC 9(4).     

We can use this way as alphanumeric as well as to check numeric.

For Eg:

MOVE CAPIN(1:4)      TO WS-ALPHAX

IF WS-ALPHAX (1:1) IS NOT NUMERIC       

   MOVE 0 TO WS-ALPHAX (1:1)

END-IF      

                                  

IF WS-NUM IS NUMERIC                  

   MOVE WS-NUM TO CAPIN2

ELSE                                          

   MOVE 0              TO CAPIN2

END-IF