Rounding numbers

JayQ

How do I use functions to round a variable in the following way:
I want variableA to be the variable rounded down to the nearest 10 decimal. For example 29->20, 34->30, 20->20,
The other one variableB should be the opposite, rounded up instead: 29->30, 34->40, 20->30

obsidian

well, you could always just write a function to handle that one for you:

function myRound($num, $dir = 'up') {
  $num /= 10;
  switch ($dir) {
    case 'up':
      $num = ceil($num);
      break;

case 'down':
  $num = floor($num);
  break;
  }

  return ($num * 10);
}

echo myRound($varA, 'down');
echo myRound($varB, 'up');

Installer

This one will match the specs 🙂 :

function round_to_ten($num, $dir = 'up')
{
    $tmp = $num / 10;
    if ($dir == 'up') {
        return (floor($tmp) + 1) * 10;
    } else {
        return floor($tmp) * 10;
    }
}

JayQ

Thanks both they do the trick 😃 theres always someone helpful in this forum I love it!

Installer

Glad to hear it. But the two functions don't always give the same results, you know.

JayQ

I have written this code:

$unique = 30
$uniquelow  = (floor($unique/10)*10);
$uniquehigh = (ceil($unique/10)*10);

However when $unique = 30 , the uniquelow and unique high becomes the same. Could there somehow be a way to do this: Make $uniquelow a random number between 20-30, and $uniquehigh be $uniquelow + 10?

So the result in this case could be 23-33, 26-36 etc.
And if $unique = 40, the result could be 33-43, 36-46 etc.

JayQ

Oh and this should only apply when $unique = 10/20/30 etc not when $unique=odd numbers like 23,44

Installer

...$uniquehigh be $uniquelow + 10?

Did you try my function? That's what it does, as requested in your original post.

Here's an even simpler way to do it:

function round_to_ten($num)
{
    $ret['low'] = floor($num / 10) * 10;
    $ret['high'] = $ret['low'] + 10;
    return $ret;
}