Interview question which I failed to answer.

arindambanerjee · New User Joined: 30 Jun 2007 Posts: 39 Location: India

Hi,

I have been asked a question in an interview as below:

CASE1:
....
A0-section.
......
Perform AB-para.
...
...

A0-Exit
Exit.

AB-Para.
...
...
Perform D-para.
....
AB-para-end.
exit.

CASE2:

...
A0-section.
......
Perform AB-para thru AB-para-end.
...
...

A0-Exit
Exit.

AB-Para.
...
...
Perform D-para.
....
AB-para-end.
exit.

D-Para is there in the code as well.
the question was whats the difference between these two cases and if there is no difference then what will be the flow.

Robert Sample · Posted: Sat Jul 11, 2009 8:54 pm

Have you reviewed the COBOL Language Reference (manuals link at the top of the page) on the PERFORM statement?

PERFORM paragraph performs only that paragraph. So case 1 would execute the PERFORM, then A8-Para, then D-para, then at the end of A8-Para would return to A0-section and continue. If there's no program exit, control would fall through A0-Exit and start executing A8-Para and so forth.

The main difference in case 2 in that execution would go through the end paragraph, but otherwise there's no difference in execution sequence.

Anuj Dhawan · Posted: Mon Jul 13, 2009 3:01 pm

There is no difference in both the approaches from execution per se as Robert has said; though at some shops coding "..thru AB-para-end" in "Perform AB-para thru AB-para-end" comes under coding standards. Every PARA should end with an EXIT though period (.) in place of EXIT would also do the same.