ARRAY 1D & 2D in COBOL

When there are multiple items of the same type, you can use arrays. A COBOL table or array is simply a data structure consisting of a collection of elements(values), all of which have the same data description, such as a table of monthly sales.

       ID DIVISION.
       PROGRAM-ID. ARRAY1.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 I PIC 9.
       01 STUDENT.
         02 STD-ID PIC 9(3) OCCURS 5 TIMES.
       PROCEDURE DIVISION.
           INITIALIZE STUDENT, I.
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 5
           ACCEPT STD-ID(I)
           END-PERFORM.
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 5
           DISPLAY STD-ID(I)
           END-PERFORM.
           STOP RUN.

2D ARRAY:

       ID DIVISION.
       PROGRAM-ID. ARRAY2.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 I PIC 9.
       01 J PIC 9.
       01 STUDENT.
         02 STD-ID OCCURS 2 TIMES.
           03 NUM PIC X(7).
           03 SUB OCCURS 2 TIMES.
             04 JCL1 PIC X(2).
             04 COBOL1 PIC X(2).
       PROCEDURE DIVISION.
           INITIALIZE I, J, STUDENT.
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 2
           ACCEPT NUM(I)
           PERFORM VARYING J FROM 1 BY 1 UNTIL J > 2
           ACCEPT SUB(I J)
           END-PERFORM
           END-PERFORM.
           PERFORM VARYING I FROM 1 BY 1 UNTIL I > 2
           DISPLAY NUM(I)
           PERFORM VARYING J FROM 1 BY 1 UNTIL J > 2
           DISPLAY SUB(I J)
           END-PERFORM
           END-PERFORM.
           STOP RUN.