IBM Mainframe Forum

by **kirangentlebreeze** » Wed Oct 27, 2010 6:42 pm

hello friends,
i am new to mainframes app programming
can any one put your ideas on how to generate random nos in cobol

by **NicC** » Wed Oct 27, 2010 6:48 pm

First check to see if there is already a BIF (Built-In Function) in COBOL - I cannot remember if there is or not, then look at the functions provided by LE (Language Environment) - it probably has. Failing that, look for an algorithm on the internet: first thing I would try for this option is google 'random number algorithm'.

by **dick scherrer** » Thu Oct 28, 2010 1:21 am

Hello and welcome to the forum,

Once determined, how will a random number be used?

by **kirangentlebreeze** » Thu Oct 28, 2010 6:49 pm

i am just a beginner in mainframes
my application needs to generate a 16 digit random no which should be unique

by **Robert Sample** » Thu Oct 28, 2010 6:58 pm

Assuming you're using Enterprise COBOL, you can use FUNCTION RANDOM to generate a sequence of "random" numbers. The COBOL Language Reference manual gives details. http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/FINDBOOK?filter=enterprise+cobol&SUBMIT=Find

by **enrico-sorichetti** » Thu Oct 28, 2010 8:26 pm

i am just a beginner in mainframes
my application needs to generate a 16 digit random no which should be unique

even if they are called random the right term should be PSEUDO RANDOM
randomness is a statistical property quite different from uniqueness which is deterministic

when testing the first call to the random number generator has a seed which is used to guarantee
that the sequence of random numbers will be the same across different runs in order to test with
consistent data
when the application is <promoted> to production the programs will have to be modified
in order to not provide the seed with the hope that each run will give a sequence of PSEUDO RANDOM numbers
( different from the previous ones )

if the main requirement is uniqueness it would be advisable to review the approach!

by **dick scherrer** » Thu Oct 28, 2010 11:56 pm

Hello,

Select all

IDENTIFICATION DIVISION.
PROGRAM-ID. EXT7.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 MIN-NUMBER PIC 99 VALUE 10.
01 MAX-NUMBER PIC 99 VALUE 20.
01 RANDOM-NUMBER PIC 99.
PROCEDURE DIVISION.
MAIN-PARA.
PERFORM 10 TIMES
COMPUTE RANDOM-NUMBER = FUNCTION RANDOM *
(MAX-NUMBER - MIN-NUMBER + 1) +
MIN-NUMBER
DISPLAY 'RANDOM NUMBER:' RANDOM-NUMBER
END-PERFORM.
STOP RUN.

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How to generate random numbers in cobol

How to generate random numbers in cobol

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