These functions DO NOT round off your values. No arbitrary precision libraries do it this way. It stops calculating after reaching scale of decimal places, which mean that your value is cut off after scale number of digits, not rounded. To do the rounding use something like this:
<?php
function bcround($number, $scale=0) {
$fix = "5";
for ($i=0;$i<$scale;$i++) $fix="0$fix";
$number = bcadd($number, "0.$fix", $scale+1);
return bcdiv($number, "1.0", $scale);
}
?>
bcscale
(PHP 4, PHP 5, PHP 7, PHP 8)
bcscale — Set or get default scale parameter for all bc math functions
Description
Sets the default scale parameter for all subsequent calls to bc math functions that do not explicitly specify a scale parameter.
Gets the current scale factor.
Parameters
-
scale -
The scale factor.
Return Values
Returns the old scale when used as setter. Otherwise the current scale is returned.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
scale is now nullable.
|
| 7.3.0 |
bcscale() can now be used to get the current scale
factor; when used as setter, it now returns the old scale value.
Formerly, scale was mandatory, and
bcscale() always returned true.
|
Examples
Example #1 bcscale() example
<?php
// default scale : 3
bcscale(3);
echo bcdiv('105', '6.55957'); // 16.007
// this is the same without bcscale()
echo bcdiv('105', '6.55957', 3); // 16.007
?>
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User Contributed Notes 4 notes
mwgamera at gmail dot com ¶
17 years ago
sicerwork at aliyun dot com ¶
7 years ago
Executing bcsacle() will change the scale value of fpm.conf, not only the current process.
ravenswd at gmail dot com ¶
12 years ago
Simple, easy way to remove excess trailing zeros using rtrim:
<php>
// $total is the result of a bcmath calculation
if ( strpos($total, '.') !== false ):
$total = rtrim($total, '0');
$total = rtrim($total, '.');
endif;
</php>
herslyadam at gmail dot com ¶
10 years ago
edited bcround function with negative number support:
<?php
function bcround($number, $scale=0) {
if($scale < 0) $scale = 0;
$sign = '';
if(bccomp('0', $number, 64) == 1) $sign = '-';
$increment = $sign . '0.' . str_repeat('0', $scale) . '5';
$number = bcadd($number, $increment, $scale+1);
return bcadd($number, '0', $scale);
}
?>
