IBM Mainframe Forum

Hi
/* factorialProgram.rex -- computes the factorial of a number */

/* Usage: exec factorialProgram number */

/* Example: exec factorialProgram 5 */

arg N .

call factorial N

say result

exit 0 /* don't fall through to the PROCEDURE instruction */

/* internal procedure FACTORIAL
* returns factorial of argument N
*/

factorial : PROCEDURE

n = arg( 1 )

if n = 1 then
return 1

return n * factorial( n - 1 )


i have given in my pds member and execcuted using the command in the ispf panel " tso exec rexx.exec(main1) exec"
rexx.exec(main1) is the dataset where i have stored the above rexx code
please help me on how to execute this
if i try this it is showing error in the line exit 0

tso exec rexx.exec(main1) exec

Why are you passing the argument 'exec' and not a number?

Also, post some real TRACE command runtime output.

And why are you posting here and not the rexx forum?

And why are you posting here and not the rexx forum?

because he wants suggestions and feedback... what else

[quote="nalinigoli"]Hi

/* main1 rexx*/
/* call factor sub program****/
pull x
say x
arg x
call factor x
say result
exit 0
factor:PROCEDURE
x = arg(1)
if x = 1
then return 1
return x * factor(x-1)

if i try this it is showing error
13 +++ return x * factor(x-1)
6 +++ call factor x
Error running MAIN1, line 13: Bad arithmetic conversion

please help me out

Your trace is not showing the values - only the statements being executed. Try TRACE '?i' for a full interactive trace. SAY the value of x before executing line 13.

What value for x are you testing with? I have tried the code you originally posted and it is giving me good results up to x = 4 so I would sugest that it is ok.

One other thing - the code does not handle invalid input! x < 1 goes into an endless loop!

can u pls give me the exact code u have executed

As I wrote 3 posts before

I have tried the code you originally posted

i.e. I cut and pasted it, loaded it to the mainframe and executed it. Afterwards I prettied it up, added the check for the parm being greater than zero and reformatted it to my own standards but what I executed first is the exact code you originally posted.