using round for the nearest multiple

[Anon]

What I want to do is first generate a random number, then round it off so that the final number is a multiple of 5.

For example use the folowing rand statement:
$randomnumber = rand(1,100);

Then use some code here to round off the number so that I only get 5, 10, 15, 20, 25, etc...

Is there anyway to do this? All the docs I find on round() are for rounding deciaml places, all my numbers will be whole!!

Thanks a lot

[Anon]

Well, what I would do is use the mod (%) operator to get the difference between the number and the multiple you are wanting (5 for what you want). I just wrote a quick function that does just that:

function round2multiple($number,$multiple) {
   $difference = $number % $multiple;
   if($number > $multiple)
      $number -= $difference;
   else
      $number = $multiple;

   return $number;
}

The function was tested on PHP 4.1.2, although it should work just fine on other versions of PHP (I see no reason it shouldn't work). Have fun, hope this helps 🙂

-Josh B

[Anon]

Thanks a lot, that did the trick