(COmmon Business Oriented Language) A high-level programming language that has been the primary business application language on mainframes and minis. It is a compiled language and was one of the first high-level languages developed. Officially adopted in 1960, COBOL stemmed from FLOWMATIC, a language developed in the mid-1950s by Grace Murray Hopper (later Rear Admiral Hopper) for the UNIVAC I.
COBOL is a very wordy language. Although mathematical expressions can also be written like other programming languages (see example below), its verbose mode is very readable for a novice. For example, multiply hourly-rate by hours-worked giving gross-pay is self-explanatory. COBOL is structured into the following divisions:
Division Name Contains IDENTIFICATION Program identification. ENVIRONMENT Types of computers used. DATA Buffers, constants, work areas. PROCEDURE The processing (program logic).
The following COBOL example converts a Fahrenheit number to Celsius. To keep the example simple, it performs the operation on the operator's terminal rather than a user terminal.
IDENTIFICATION DIVISION. PROGRAM-ID. EXAMPLE. ENVIRONMENT DIVISION. CONFIGURATION SECTION. SOURCE-COMPUTER. IBM-370. OBJECT-COMPUTER. IBM-370. DATA DIVISION. WORKING-STORAGE SECTION. 77 FAHR PICTURE 999. 77 CENT PICTURE 999. PROCEDURE DIVISION. DISPLAY 'Enter Fahrenheit ' UPON CONSOLE. ACCEPT FAHR FROM CONSOLE. COMPUTE CENT = (FAHR- 32) * 5 / 9. DISPLAY 'Celsius is ' CENT UPON CONSOLE. GOBACK.
IBM COBOLs
In 1994, IBM dropped support of OS/VS COBOL, which conforms to ANSI 68 and ANSI 74 standards and limits a program's address space to 16 bits. IBM's VS COBOL II (1984) and COBOL/370 (1991) conform to ANSI 85 standards and provide 31-bit addressing, which allows programs to run "above the line."
COBOL/370 is more compliant with AD/Cycle, has more string, math and date functions, including four-digit years, allows development through a PC window and provides enhanced runtime facilities.
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