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Posted: **14 Nov 2009 10:01**

I am new at batch file programming (very new), and I tried to make a batch file that would give the factorial of a number between 1 and 10

After fixing any issues with the first line of text, I tried it again and it looped the message "The syntax is incorrect".

For those who don't know, the factorial of a number "x" is 1*2*3*4*...*x
E.g. 4 factorial is 1*2*3*4=24

here is the code, I know there probably are hundreds of mistakes.

Code: Select all

@echo off
if ("%1" GTR "10") (goto :bad) else (goto :good)

:bad
echo The number is too big

:good
set %n%=1
goto :math

:math
set %m%=%n%+1
if /i not (%m% GTR %1) (goto :matha) else (goto :end)

:matha
set %r%=%b%*%m%
set %b%=%r%
set %n%=%m%
goto :math

:end
echo %1 factorial is %r.
pause
@echo on
cls

Posted: **14 Nov 2009 17:34**

Ok, I fixed a few mistakes, but now it outputs %_result% as nothing. Also, the first IF line that checks whether the number is greater than 10 doesn't work

Code: Select all

@echo off
if "%1" GTR 10 (goto :bad) else (goto :good)

:bad
echo The number is too big
goto :rend

:good
set /A _number=1
set /A _preres=1
goto :math

:math
set /A _number+=1
if ("_number" LEQ "%1") (goto :matha) else (goto :end)

:matha
set  
set /A _result=_number*_preres
set /A _preres=_result
goto :math

:end
echo %1 factorial is %_result%.
goto :rend

:rend
pause
@echo on
cls

________________

EDIT:

Nevermind, I made everything easier with a FOR loop and fixed the problem:

Code: Select all

@echo off
set /a _res=1
FOR /l %%n IN (1,1,%1) DO set /A _res*=%%n
echo %_res%
@echo on

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Need help with syntax

Need help with syntax

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