编程语言 COBOL

Overview

COBOL (Common Business-Oriented Language) is one of the oldest high-level programming languages that was developed in the late 1950s. It was primarily designed for business, finance, and administrative systems for companies and governments. Despite its age, COBOL is still widely used today in legacy systems due to its stability and reliability.

Syntax

COBOL syntax is known for its verbosity and readability. It uses English-like language elements such as verbs, nouns, clauses, and sentences to make it easy for non-programmers to understand. Some key syntax features of COBOL include:

• Division: COBOL programs are divided into four divisions - Identification, Environment, Data, and Procedure.
• Paragraphs: Code in COBOL is organized into paragraphs, which are made up of statements.
• Data Types: COBOL supports various data types such as alphanumeric, numeric, and monetary.
• Arithmetic Operations: COBOL provides arithmetic operations for performing calculations.
• Conditional Statements: COBOL includes conditional statements like IF-ELSE for decision-making.

Here is a simple COBOL program that displays "Hello, World!":

IDENTIFICATION DIVISION.
PROGRAM-ID. HELLO-WORLD.

PROCEDURE DIVISION.
    DISPLAY 'Hello, World!'.
    STOP RUN.

Developer Toolchain

COBOL development typically requires specific tools and environments due to its legacy nature. Some popular COBOL development tools include:

• Visual COBOL: A modern IDE that integrates COBOL development with popular tools like Visual Studio and Eclipse.
• Micro Focus COBOL: A suite of tools for COBOL development, testing, and deployment.
• IBM Enterprise COBOL: IBM's COBOL compiler for z/OS mainframe systems.
• GNU COBOL: An open-source COBOL compiler that supports various platforms.

In addition to these tools, COBOL developers often work with legacy systems, databases, and mainframes to maintain and modernize existing COBOL applications.