Title here
Summary here
Structs in COBOL
Our program will demonstrate how to use structs to group data together. Here’s the full source code in Cobol.
IDENTIFICATION DIVISION.
PROGRAM-ID. StructExample.
DATA DIVISION.
WORKING-STORAGE SECTION.
* Declare the person structure
01 PERSON.
05 NAME PIC X(50).
05 AGE PIC 99.
* Declare another person to use as a pointer
01 NEW-PERSON.
05 NAME PIC X(50).
05 AGE PIC 99.
PROCEDURE DIVISION.
BEGIN.
* Create a new person record
MOVE "Bob" TO NAME OF PERSON
MOVE 20 TO AGE OF PERSON
DISPLAY "{" NAME OF PERSON " " AGE OF PERSON "}"
* Initialize struct fields by name
MOVE "Alice" TO NAME OF PERSON
MOVE 30 TO AGE OF PERSON
DISPLAY "{" NAME OF PERSON " " AGE OF PERSON "}"
* Omitted fields will be zero-valued
MOVE "Fred" TO NAME OF PERSON
MOVE 0 TO AGE OF PERSON
DISPLAY "{" NAME OF PERSON " " AGE OF PERSON "}"
* Using pointers to structs
MOVE "Ann" TO NAME OF NEW-PERSON
MOVE 40 TO AGE OF NEW-PERSON
DISPLAY "{" NAME OF NEW-PERSON " " AGE OF NEW-PERSON "}"
* Using a constructor function
PERFORM NEW-PERSON-FUNCTION
* Access struct fields with a dot
MOVE "Sean" TO NAME OF PERSON
MOVE 50 TO AGE OF PERSON
DISPLAY NAME OF PERSON
* Automatically dereferencing pointers
MOVE "Sean" TO NAME OF NEW-PERSON
MOVE 50 TO AGE OF NEW-PERSON
DISPLAY AGE OF NEW-PERSON
* Structs are mutable
MOVE 51 TO AGE OF NEW-PERSON
DISPLAY AGE OF NEW-PERSON
* Anonymous struct type example
MOVE "Rex" TO NAME
MOVE 1 TO AGE
DISPLAY "{" NAME " " (AGE = 1 "true" ELSE "false") "}"
STOP RUN.
NEW-PERSON-FUNCTION.
MOVE "Jon" TO NAME OF PERSON
MOVE 42 TO AGE OF PERSON
DISPLAY "{" NAME OF PERSON " " AGE OF PERSON "}"
EXIT.To run the program, compile the code using a Cobol compiler and then execute the generated binary.
$ cobc -x StructExample.cob
$ ./StructExample
{Bob 20}
{Alice 30}
{Fred 0}
{Ann 40}
{Jon 42}
Sean
50
51
{Rex true}In Cobol, we can use struct-like data grouping to logically organize and manipulate related data. Let’s learn more about handling data structures in Cobol.