bcscale

(PHP 4, PHP 5, PHP 7, PHP 8)

bcscale — Set or get default scale parameter for all bc math functions

Опис

bcscale(int $scale): int

Sets the default scale parameter for all subsequent calls to bc math functions that do not explicitly specify a scale parameter.

bcscale(null $scale = null): int

Gets the current scale factor.

Параметри

scale: The scale factor.

Значення, що повертаються

Returns the old scale when used as setter. Otherwise the current scale is returned.

Журнал змін

Версія	Опис
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`.

Приклади

Приклад #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

down

mwgamera at gmail dot com ¶

16 years ago

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);
        }
?>

down

sicerwork at aliyun dot com ¶

7 years ago

Executing bcsacle() will change the scale value of fpm.conf, not only the current process.

down

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>

down

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);
}
?>

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