COBOL interview question on PERFORM VARYING.

[utkarsh]

Hi,

Please guide on this interview question, What is the content of RESULT after execution of the following COBOL instruction. The start value of RESULT is 0.

Code: Select all

PERFORM VARYING C FROM 1 BY 1 UNTIL C = 6
ADD 1 TO RESULT
END-PERFORM

[Robert Sample]

Code is

Code: Select all

77  C                         PIC 9(04) COMP. 
77  RESULT                    PIC 9(04).      
                                              
PROCEDURE DIVISION.                           
000-START.                                    
    PERFORM VARYING C FROM 1 BY 1 UNTIL C = 6 
    ADD 1 TO RESULT                           
    END-PERFORM.                              
                                              
    DISPLAY 'C= ' C ' RESULT= ' RESULT.       

with results of

Code: Select all

C= 0006 RESULT= 0005  

The test is performed before the execution of the loop and hence these results.

[utkarsh]

Thank you for your detailed explnation, really helpful.

Is it possible to test such cases on personal computer as these days I am on bench and don't have mainframe access.

[Robert Sample]

Yes. GnuCOBOL is available to download for various platforms including Windows and Linux. GnuCOBOL has standard COBOL support, and I've run mainframe (Enterprise COBOL) program on it with no issues.

[utkarsh]

Thanks Robert. I tried downloaded GnuCOBOL, installing it and I can not make it work. Instructions are not very clear. Could you or someone guide on how to install GnuCOBOL on laptop?