从数字中取出X小数位数

Question

I have let's say 0.00001004 or 0.00001

I am trying to choose and how decimal places to prune off and turn both of those so it returns 0.00001 both times.

I do not want it to round the number in anyway.

I've tried this but it is not giving me the desired results.

function decimalFix($number, $decimals) { 
   return floatval(bcdiv($number, 1, $decimals)); 
}

echo decimalFix(0.00001, 5); // returns "0"

Does anyone know what I can do? I can't have any rounding involved and I need it to return it as a float and not a string.

Answer 1

There's a function that does exactly this in the first comment on the PHP documentation for floor(). I'll copy it here in case it disappears from there, but credits go to seppili_:

function floordec($zahl,$decimals=2){    
     return floor($zahl*pow(10,$decimals))/pow(10,$decimals);
}

Use it like:

$number = 0.00001004;

$rounded = floordec($number, 5);
var_dump($rounded); // float(0.00001)

Edit: There's a comment further down on that page by Leon Grdic that warns about float precision and offers this updated version:

function floordec($value,$decimals=2){    
    return floor($value*pow(10,$decimals)+0.5)/pow(10,$decimals);
}

Usage is the same.