Ch 12_1. Array and Tables (I)


To calculate average temp. of a day

   01  TEMP-REC.
       03 1-AM   PIC   S9(3).
       03 2-AM   PIC   S9(3).
       03 3-AM   PIC   S9(3).
       ...
       03 12-PM  PIC   S9(3).
       
       ...
       COMPUTE AVG-TEMP = (1-AM + 2-AM + ... + 12-PM) / 24

How about average temp. of a year

   01  TEMP-REC.
       03 JAN1   PIC   S9(3).
       03 JAN2   PIC   S9(3).
       ...
       03 DEC31  PIC   S9(3).
  
       ...
Would require a great deal of coding!

Introducing ARRAY

   01  TEMP-REC.
       03 T   OCCURS   24 TIMES  PIC 9(3).

How to access ARRAY elements

   T (1)
   T (2)

   T (24)

To calculate average temp. of a day using ARRAY

     MOVE 0 To TOT-TEMP
     PERFORM varying SUB from 1 by 1 until SUB > 24
        ADD T (SUB) TO TOT-TEMP
     END-PERFORM 
     COMPUTE AVG-TEMP = TOT-TEMP / 24