Subprograms

CALL and INVOKE call subprograms and methods, respectively.

COBOL-74 added subprograms, giving programmers the ability to control the data each part of the program could access.

However, coroutines mean that multiple subprograms have execution state – rather than a single call stack of subroutines – and thus introduce a different form of complexity.

It is very rare for subprograms to allow entry to an arbitrary position in the subprogram, as in this case the program state (such as variable values) is uninitialized or ambiguous, and this is very similar to a goto.

Subroutines Subroutines ; callable units such as procedures, functions, methods, or subprograms are used to allow a sequence to be referred to by a single statement.