MVSFORUMS.com

[misi01]

Just talked to a colleague and we were discussing the above as the ending statement in a section. Where I work, we do not use perform x thru y - only perform on a section. In addition, we allow the use of GO TO as long as it only goes to the end of the section.

Personally, I always use the word exit, since, for me, semantically, CONTINUE could be interpreted as continue on to the next line (I know it doesn't). EXIT, for me, clearly says leave this section. In addition, you have the "ugly" scenario of a possible

[dbzTHEdinosauer]

misi01,

by definition, an EXIT statement is treated as a CONTINUE - no operational command present.

That said,
EXIT allows one to define a Paragraph - for the end of a PERFORM THRU.

i disagree with the statement

[NorthernDancer]

I have always used SECTIONs instead of PARAGRAPHS. And only GO TO the xxxxxxxx-SECTION-EXIT. EXIT. to get out. I've always found it makes things easier and clearer to understand. A lot of Programmer I've found don't understand the concept, so don't know how to write using it. At one time years ago, I and another peer found that by using SECTIONs, there cannot be a Fall Through. Don't know if that's still true, but it never happens to me using this method.

[William Collins]

Using SECTIONS with any IBM Cobol I know of will not prevent "Fall Through".

Neither the direct "Fall Through" where the main body of code fails to STOP RUN or GOBACK and just "drops" into a SECTION, nor the GO TO to something outside the SECTION currently being performed.

Strange things happen if either of the above are coded in error (or by design, by people who don't know). There is nothing you can do to prevent "Fall Through" except by coding correctly.

[misi01]

if you only use perform on sections and no perform through ....., and assuming all your sections have the word SECTION. included, can you show a scenario where you could fall through ?
_________________
Michael

[William Collins]

[NorthernDancer]

I would never use a structure like DEEPDOO in a Production Commercial Application. Has too many GO TOs in it defeating the purpose of part of the original posting. Yikes reminds me of some awful Honeywell GCOS COBOL PGMs from the past G(od's) C(hosen) O(perating) S(ystem) !!

[William Collins]

I see I didn't make it clear in the "remarks". Definitely, definitely, definitely, not for use in any way, shape or form except to show that leaving PERFORM ranges "active" can give you "interesting" and non-obvious results.

Other than that, the remaining purpose could be deliberate obfuscation, I suppose.

Written after someone came to me with a problem and did not believe my explanation.

[delta403]

First let me describe the difference between EXIT and Continue;
Exit - It will come out the section and control will flow down the section; You can use this, when your program is written in the form of Top to bottom structure.

Continue - will send the control out of the pragraph/section and back to the statment from where the last section was called. Good practice to use this.

Please let me know if you have any question.

[William Collins]

delta403,

Did you read the post by dbzTHEdinosauer above? "By definition" means "as the manual says".

Your explanation makes no sense, either in itself or when reviewed against the manual.

EXIT "does" nothing. CONTINUE "does" nothing. They are both used at points where the compiler is generating "branches", as in gotos, anyway, so whether present or not the resultant code will be the same.

Try using them interchangeably in a little program you compile, then review the results against your explanation.