How do I get a float value when dividing two integers? (PHP)

user1869257 picture user1869257 · Jun 20, 2013 · Viewed 38k times · Source

Hi I am trying to divide two integers ex: 12/13 but I always get a whole integer 1 not a decimal number.

I tried type casting the values to float before hand with no success.

Basically all I want is a decimal result like: 0.923...

$x = 12;
$y = 13;
echo $value = $x / $y; //Would like to see 0.923 not 1

Answer

CSᵠ picture CSᵠ · Jun 20, 2013

Under normal circumstances your code should return the floating value 0.923076...

The reason you get a rounded integer might be because you have your ini setting for "precision" set to 0, to fix this either edit your php.ini or use ini_set("precision", 3); in your code before the calculation.

Another way to workaround this is to use BCmath:

echo $value=bcdiv($a, $b, 3);

And yet another way without using any extension is to use a little math trick by multiplying the value you want to divide by 1000 to get 3 decimals.
This way you'll divide 12000 by 13 and the whole part will be 923, then since you multiplied by 1e3 insert a comma/dot before the last most 3 places.

function divideFloat($a, $b, $precision=3) {
    $a*=pow(10, $precision);
    $result=(int)($a / $b);
    if (strlen($result)==$precision) return '0.' . $result;
    else return preg_replace('/(\d{' . $precision . '})$/', '.\1', $result);
}

echo divideFloat($a, $b); // 0.923