COBOL Single Dimension Array with Index Example

Table Processing Tutorial   

Scenario - Accessing single dimensional array using index.

Requirement - Let us declare a table to process two student details. WS-CLASS is the group variable and WS-STUDENT is a variable with student information OCCURS 2 times to capture the two students information.

Code -

----+----1----+----2----+----3----+----4----+----5----+
      * Single Dimentional Table
       IDENTIFICATION DIVISION.
       PROGRAM-ID. SINDIMIX.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
	  * Declaring the array with Index
       01 WS-CLASS.
          03 WS-STUDENT  OCCURS 2 TIMES INDEXED BY IDX-ONE.
             05 WS-ROLL-NO      PIC X(03).
             05 WS-NAME         PIC X(10).

       PROCEDURE DIVISION.

      *    Populating array occurrences
           MOVE "001PAWAN Y" TO WS-STUDENT(1).
           MOVE "002KUMAR Y" TO WS-STUDENT(2).

           DISPLAY "Class Information: " WS-CLASS.
           DISPLAY " "

      *    Initializing Index
           SET IDX-ONE        TO 1.
           DISPLAY "Students Information   => "
		   
	  *    Loop for displaying two students information
           PERFORM UNTIL IDX-ONE > 2
               DISPLAY "Roll No:  " WS-ROLL-NO (IDX-ONE)
               DISPLAY "Name:     " WS-NAME (IDX-ONE)

	  *	       Increasing the Index by 1
               SET IDX-ONE UP BY 1
           END-PERFORM.

           STOP RUN.

JCL -

//MATEPKRJ JOB MSGLEVEL=(1,1),NOTIFY=&SYSUID             
//*                                                      
//STEP01  EXEC PGM=SINDIMIX                              
//STEPLIB  DD  DSN=MATEPK.COBOL.LOADLIB,DISP=SHR         
//SYSOUT   DD  SYSOUT=*

Output -

Class Information: 001PAWAN Y   002KUMAR Y 

Students Information   =>
Roll No:  001
Name:     PAWAN Y
Roll No:  002
Name:     KUMAR Y

Explaining Example -

In the above example:

  • WS-STUDENT(1) represents first student information and WS-STUDENT(2) represents second student information.
  • IDX-ONE is index declared on WS-STUDENT single dimensional array. The index is initialized and incremented using SET statement.
  • WS-ROLL-NO(1), WS-NAME(1) represents first student roll number and name. similarly, WS-ROLL-NO(2), WS-NAME(2) represents the second student roll number and name.
  • WS-CLASS represents the full class informaton. i.e., two students information - WS-STUDENT(1) and WS-STUDENT(2).