Re: Stylistic note on loops
On Mon, 8 Nov 2010, Martin Gregorie wrote:
On Sun, 07 Nov 2010 15:08:04 -0800, Nick Keighley wrote:
COBOL programmers are supposedly unaware of what a global variable
is (allegedly everything is global).
There's no allegedly about it: global is a non-term in COBOL. All data
items are defined in one section or another of the program's DATA
DIVISION and have the same scope, i.e. all data is accessible by any
executable statement in the program. The sections of the data division
are functional in that they define how the data in a section is used:
- items in the file section can be read and written with file i/o
- items in linkage section are are the formal arguments if the program
is callable
- items in working-storage are private to the program in the Java sense
of private.
How big is a typical 'program'? If it's the size of a class, then COBOL's
implicit 'global' is really an implicit 'private static'; if it's the size
of a package, then it's really an implicit '/* default */ static'. If it's
the size of an application, then it really is global, and i can imagine
pain results.
A bit of googling reveals that there are various extensions to COBOL for
things like local variables, thread-locals, making programs recursive or
reentrant, etc. And of course there's an Object COBOL.
So, whilst it may be true that for most of its life, and for the time when
it was most important, COBOL's programmers talked as much about global
variables as fish do about water, but i doubt that's been true since, i
would guess, 1990.
tom
--
The future will accost us with boob-slapping ferocity. -- H. G. Wells