COBOL - technical definition

(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.