Why is the second if statement in this Cobol code not being evaluated (OpenCOBOL)?

Question

   identification division.
   program-id.      quick.
   environment division.
   data division.
   working-storage section.
   01 temp-val1 pic 9 value 1.
   01 temp-val2 pic 9 value 2.
   procedure division.
    mainline.
           perform encrypt.
           stop run.
    encrypt.
           if (temp-val1 = 1)
             display "1"
             display "2".
           end_if.
           if (temp-val2 = 2)
             display "2"
             display "1".
           end_if.
           display "outside the ifs".

The output of the program is simply:
1
2

But I would expect:

1
2
2
1
outside the ifs

What am I doing wrong? Have I misunderstood the sentence structure for the statements inside the first if, or the placement of the periods?

You are mixing up COBOL coding styles. This is resulting in unexpected transfer of control. Check out [COBOL Transfer of Control](http://www3.sympatico.ca/bredam/TransferControl.html). That said, I would have expected the compiler to have thrown an error or at least a warning on your `end-if.` — NealB, Apr 18 '13 at 17:06
OK, not a compiler bug once luke has spotted the problem. Serves me right for looking at the nicer examples, rather than the code in the question :-) — Bill Woodger, Apr 19 '13 at 13:55

score 4 · Accepted Answer · edited Apr 18 '13 at 17:58

4

There are 2 problems with the code. One is the period just before the end-if.

The other is that end_if is not the same as end-if. Only end-if is used in Cobol. The end_if is being taken as a paragraph name. Therefore, it does not (and should not) produce a compiler warning message.

edited Apr 18 '13 at 17:58

McCee

1,549
10
19

answered Apr 18 '13 at 17:32

luke

56
1

Sharp eyes... That would make two paragraphs having the same name (END_IF). I don't think this is "illegal", just unconventional. I also believe the compiler should throw an error/warning if there been a reference to one of these occurances (eg. PERFORM END_IF) because the name could not be uniquely resolved. – NealB Apr 18 '13 at 20:51
This is the correct answer, as it explains (mostly) why there was no error reported by the compiler either. The end_if as a paragraph causes the PERFORM of encrypt to end having just done the one IF. The unreferenced duplicate paragraph names presumably are "valid", although since neither are in a SECTION they could never be referenced (they would both need to be, I think, in SECTIONs to be truly valid if referenced). Fixed-format COBOL gives some extra possibilities for diagnosing a problem, like " should begin in Area A" :-) – Bill Woodger Apr 19 '13 at 12:56

score 2 · Answer 2 · answered Apr 17 '13 at 19:27

Trial and error proves out that the issue is a mix of syntax and period placement errors.

This did the trick to provide the expected output.

   identification division.
   program-id.      quick.
   environment division.
   data division.
   working-storage section.
   01 temp-val1 pic 9 value 1.
   01 temp-val2 pic 9 value 2.
   procedure division.
    mainline.
           perform encrypt.
           stop run.
    encrypt.
           IF (temp-val1 = 1)
             display "1"
             display "2"
           END-IF
           if (temp-val2 = 2)
             display "2"
             display "1"
           END-IF
           display "outside the ifs".

The example code in the openCobol Programmer's guide helped me resolve the issue. http://opencobol.add1tocobol.com/OpenCOBOL%20Programmers%20Guide.pdf

score 1 · Answer 3 · answered Apr 18 '13 at 01:22

1

To spell it out bluntly

    display "2".
   end_if.

the '.' after "2" ends the if statement, then you have another end_if and . which Open-Cobol is probably taking as end of procedure - probably not the best interpretation.

As Nick said **Do not mix coding styles.

personnaly I would put one '.' on a line by itself at the end of each procedure

encrypt.
           IF (temp-val1 = 1)
             display "1"
             display "2"
           END-IF
           if (temp-val2 = 2)
             display "2"
             display "1"
           END-IF
           display "outside the ifs"

           .

answered Apr 18 '13 at 01:22

Bruce Martin

10,358
1
27
38

Looks good. You'd hope for a compile error for the, by that time, "stray" end-ifs. It is not only the second IF which is not done, but the DISPLAY which follows as well, so I think you're correct about it wandering away from the paragraph. – Bill Woodger Apr 18 '13 at 10:32
Yes, sorry to be unclear. That's what I meant by a "compile error". The fact that there is no "compile error" points to a "compil*er* error" if the version is up-to-date. If an "old" version of the compiler, could well have been fixed. I do not know of any Cobol which would successfully compile that. There should be the same syntax-error noted by the compiler twice. – Bill Woodger Apr 18 '13 at 12:45
I like this style of placing the single period at the end of a paragraph for clarity's sake. Thanks for the tip! – NickAbbey Apr 19 '13 at 16:57

Why is the second if statement in this Cobol code not being evaluated (OpenCOBOL)?

3 Answers3