IDENTIFICATION DIVISION.
PROGRAM-ID. SwapValues.

DATA DIVISION.
WORKING-STORAGE SECTION.
01 Array-Sum PIC 9(4).
01 Array-SIZE PIC 9(4).
01 Array OCCURS 100 TIMES.
   02 Array-Value PIC 9.

01 Min-Swaps PIC 9(4).
01 Left-Index PIC 9(4) VALUE 1.
01 Right-Index PIC 9(4) VALUE 1.
01 Temp PIC 9.

PROCEDURE DIVISION.
BEGIN.
    ACCEPT Array-SIZE.
    PERFORM READ-ARRAY.
    PERFORM SWAP-VALUES UNTIL Left-Index >= Right-Index.
    DISPLAY Min-Swaps.
    STOP RUN.

READ-ARRAY.
    PERFORM VARYING Left-Index FROM 1 BY 1 UNTIL Left-Index > Array-SIZE
        ACCEPT Array(Left-Index)
    END-PERFORM.

SWAP-VALUES.
    PERFORM UNTIL Array(Left-Index) = Array(Right-Index)
        PERFORM UNTIL Array(Left-Index) = 1
            ADD 1 TO Left-Index
        END-PERFORM
        PERFORM UNTIL Array(Right-Index) = 0
            SUBTRACT 1 FROM Right-Index
        END-PERFORM
        IF Left-Index < Right-Index
            MOVE Array(Left-Index) TO Temp
            MOVE Array(Right-Index) TO Array(Left-Index)
            MOVE Temp TO Array(Right-Index)
            ADD 1 TO Min-Swaps
        END-IF
    END-PERFORM.

COBOL online compiler

Write, Run & Share COBOL code online using OneCompiler's COBOL online compiler for free. It’s a reliable and accessible playground to practice and run COBOL code with ease. The compiler supports classic COBOL syntax and is great for learning, teaching, and experimenting with business logic programs.

About COBOL

COBOL (Common Business-Oriented Language) is a high-level programming language developed in the 1950s. It is primarily used in business, finance, and administrative systems for companies and governments. COBOL is known for its English-like syntax and is still widely used in legacy enterprise systems.

Sample Code

The following is a simple COBOL program that prints a greeting:

IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO.
PROCEDURE DIVISION.
    DISPLAY "Hello, OneCompiler!".
    STOP RUN.

Taking inputs

In COBOL, input is typically handled using the ACCEPT keyword. Here’s an example that takes user input and prints it back.

IDENTIFICATION DIVISION.
PROGRAM-ID. GREET.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 USER-NAME PIC A(30).

PROCEDURE DIVISION.
    DISPLAY "Enter your name: ".
    ACCEPT USER-NAME.
    DISPLAY "Hello, " USER-NAME "!".
    STOP RUN.

Syntax Basics

Program Structure

COBOL programs are divided into four divisions:

  • IDENTIFICATION DIVISION: Program metadata
  • ENVIRONMENT DIVISION: Machine/environment details (optional)
  • DATA DIVISION: Variable declarations
  • PROCEDURE DIVISION: Actual program logic

Variables

Variables are declared in the DATA DIVISION using PIC clauses.

01 AGE        PIC 99.
01 NAME       PIC A(20).
01 SALARY     PIC 9(5)V99.

Displaying and Accepting Data

DISPLAY "Welcome to COBOL!".
ACCEPT USER-INPUT.

Conditional Statements

IF AGE >= 18
    DISPLAY "Eligible to vote."
ELSE
    DISPLAY "Not eligible."
END-IF.

Loops (PERFORM)

PERFORM VARYING I FROM 1 BY 1 UNTIL I > 5
    DISPLAY "Count: " I
END-PERFORM.

This guide provides a quick reference to COBOL programming syntax and features. Start coding in COBOL using OneCompiler’s COBOL online compiler today!