COBOL
COBOL (/ˈkoʊbɒl, -bɔːl/; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural and, since 2002, object-oriented language. COBOL is primarily used in business, finance, and administrative systems for companies and governments. COBOL is still widely used in applications deployed on mainframe computers, such as large-scale batch and transaction processing jobs. Many large financial institutions were developing new systems in the language as late as 2006, but most programming in COBOL today is purely to maintain existing applications. Programs are being moved to new platforms, rewritten in modern languages or replaced with other software.
The COBOL 60 report to CODASYL (April 1960) | |
| Paradigm | Procedural, imperative, object-oriented, generic |
|---|---|
| Designed by | Howard Bromberg, Norman Discount, Vernon Reeves, Jean E. Sammet, William Selden, Gertrude Tierney, with indirect influence from Grace Hopper |
| Developers | CODASYL, ANSI, ISO/IEC |
| First appeared | 1959 |
| Stable release | ISO/IEC 1989:2023
/ 2023 |
| Typing discipline | Weak, static |
| Filename extensions | .cbl, .cob, .cpy |
| Major implementations | |
| GnuCOBOL, IBM COBOL, Micro Focus Visual COBOL | |
| Dialects | |
| COBOL/2, DEC COBOL-10, DEC PDP-11 COBOL, DEC PDP-11 COBOL-85, DEC VAX COBOL, DOSVS COBOL, Envyr ICOBOL, Fujitsu COBOL, Hitachi COBOL2002, HP3000 COBOL/II, IBM COBOL SAA, IBM COBOL/400, IBM COBOL/II, IBM Enterprise COBOL, IBM ILE COBOL, IBM OS/VS COBOL, ICL COBOL (VME), Micro Focus ACUCOBOL-GT, Micro Focus COBOL-IT, Micro Focus RM/COBOL, Micro Focus Visual COBOL, Microsoft COBOL, Raincode COBOL, Realia COBOL, Ryan McFarland RM/COBOL, Ryan McFarland RM/COBOL-85, Tandem (NonStop) COBOL, Tandem (NonStop) SCOBOL, UNIVAC COBOL, Unisys MCP COBOL74, Unisys MCP COBOL85, Unix COBOL X/Open, Veryant isCOBOL, Wang VS COBOL | |
| Influenced by | |
| Initial: AIMACO, COMTRAN, FACT, FLOW-MATIC
COBOL 2002: C++, Eiffel, Smalltalk | |
| Influenced | |
| CobolScript, EGL, PL/I, PL/B | |
| |
COBOL was designed in 1959 by CODASYL and was partly based on the programming language FLOW-MATIC designed by Grace Hopper. It was created as part of a U.S. Department of Defense effort to create a portable programming language for data processing. It was originally seen as a stopgap, but the Defense Department promptly forced computer manufacturers to provide it, resulting in its widespread adoption. It was standardized in 1968 and has been revised five times. Expansions include support for structured and object-oriented programming. The current standard is ISO/IEC 1989:2023.
COBOL statements have prose syntax such as MOVE x TO y, which was designed to be self-documenting and highly readable. However, it is verbose and uses over 300 reserved words. This contrasts with the succinct and mathematically inspired syntax of other languages (in this case, y = x;).
COBOL code is split into four divisions (identification, environment, data, and procedure) containing a rigid hierarchy of sections, paragraphs and sentences. Lacking a large standard library, the standard specifies 43 statements, 87 functions and just one class.
Academic computer scientists were generally uninterested in business applications when COBOL was created and were not involved in its design; it was (effectively) designed from the ground up as a computer language for business, with an emphasis on inputs and outputs, whose only data types were numbers and strings of text.
COBOL has been criticized for its verbosity, design process, and poor support for structured programming. These weaknesses result in monolithic programs that are hard to comprehend as a whole, despite their local readability.
For years, COBOL has been assumed as a programming language for business operations in mainframes, although in recent years, many COBOL operations have been moved to cloud computing.