給 Java 工程師的 COBOL 快速入門

COBOL 教學文

COBOL 中文入門地圖（概覽）

COBOL vs Java 語法對照表

功能 COBOL Java
主程式起始 PROGRAM-ID. HelloWorld. public class HelloWorld {
顯示文字 DISPLAY "Hello" System.out.println("Hello");
變數宣告 01 AGE PIC 99. int age;
流程控制 IF AGE > 18 THEN ... if (age > 18) {...}
區塊與縮排 以 DIVISION/SECTION 結構劃分 以 { } 區塊劃分
結束程式 STOP RUN. return;

語法教學

1. Cobol 的架構教學

Cobol 程式的基本架構包含四個主要 Division，每個 Division 有不同的用途。

2. Cobol 架構範例

IDENTIFICATION DIVISION.
PROGRAM-ID. HelloWorld.

ENVIRONMENT DIVISION.

DATA DIVISION.
WORKING-STORAGE SECTION.
    01 MESSAGE PIC X(20) VALUE 'Hello, Cobol!'.

PROCEDURE DIVISION.
    DISPLAY MESSAGE.
    STOP RUN.

3. 正確的區域劃分教學

4. 區域劃分範例

       IDENTIFICATION DIVISION.
       PROGRAM-ID. ExampleProgram.

       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 NUM1  PIC 9(2) VALUE 10.
       01 NUM2  PIC 9(2) VALUE 20.
       01 RESULT PIC 9(3).

       PROCEDURE DIVISION.
           ADD NUM1 TO NUM2 GIVING RESULT.
           DISPLAY 'The result is: ' RESULT.
           STOP RUN.

範例程式碼

範例一：簡單加法

IDENTIFICATION DIVISION.
PROGRAM-ID. SimpleAddition.
DATA DIVISION.
WORKING-STORAGE SECTION.
    01 NUM1 PIC 9(2) VALUE 10.
    01 NUM2 PIC 9(2) VALUE 20.
    01 RESULT PIC 9(3).
PROCEDURE DIVISION.
    ADD NUM1 TO NUM2 GIVING RESULT.
    DISPLAY 'The result of addition is: ' RESULT.
    STOP RUN.

範例二：判斷年齡

IDENTIFICATION DIVISION.
PROGRAM-ID. AgeCheck.
DATA DIVISION.
WORKING-STORAGE SECTION.
    01 AGE PIC 9(2).
PROCEDURE DIVISION.
    DISPLAY 'Enter your age: '.
    ACCEPT AGE.
    IF AGE >= 18 THEN
        DISPLAY 'You are an adult.'
    ELSE
        DISPLAY 'You are a minor.'.
    STOP RUN.

實作題目