<?php
/**
* my_bcmod - get modulus (substitute for bcmod)
* string my_bcmod ( string left_operand, int modulus )
* left_operand can be really big, but be carefull with modulus :(
* by Andrius Baranauskas and Laurynas Butkus :) Vilnius, Lithuania
**/
function my_bcmod( $x, $y )
{
// how many numbers to take at once? carefull not to exceed (int)
$take = 5;
$mod = '';
do
{
$a = (int)$mod.substr( $x, 0, $take );
$x = substr( $x, $take );
$mod = $a % $y;
}
while ( strlen($x) );
return (int)$mod;
}
// example
echo my_bcmod( "7044060001970316212900", 150 );
?>
bcmod
(PHP 4, PHP 5, PHP 7, PHP 8)
bcmod — Get modulus of an arbitrary precision number
Description
Get the remainder of dividing num1 by
num2.
Unless num2 is zero, the result has the same sign
as num1.
Parameters
-
num1 -
The dividend, as a string.
-
num2 -
The divisor, as a string.
Return Values
Returns the modulus as a string, or null if
num2 is 0.
Changelog
| Version | Description |
|---|---|
| 8.0.0 |
scale is now nullable.
|
| 7.2.0 |
num1 and num2 are no
longer truncated to integer, so now the behavior of
bcmod() follows fmod() rather than
the % operator.
|
| 7.2.0 |
The scale parameter was added.
|
Examples
Example #1 bcmod() example
<?php
bcscale(0);
echo bcmod( '5', '3'); // 2
echo bcmod( '5', '-3'); // 2
echo bcmod('-5', '3'); // -2
echo bcmod('-5', '-3'); // -2
?>Example #2 bcmod() with decimals
<?php
bcscale(1);
echo bcmod('5.7', '1.3'); // 0.5 as of PHP 7.2.0; 0 previously
?>
add a note
User Contributed Notes 2 notes
lauris at night dot lt ¶
20 years ago
drahoszdenek at gmail dot com ¶
11 years ago
The modulus can be only integer. For "floats" bcmod returns 0:
<?php
echo bcmod('10', '2.1'); // 0
?>
For real modulus you can use BN-PHP project (hosted at Bitbucket):
<?php
$eval = new \BN\Expression\ExpressionEvaluator();
$operators = new \BN\Expression\OperatorsFactory();
$eval->setOperators($operators->getOperators(array('%')));
echo $eval->evaluate('10 % 2.1'); // 1.6
echo $eval->evaluate('10 % -2.1'); // 1.6
echo $eval->evaluate('-10 % 2.1'); // -1.6
echo $eval->evaluate('-10 % -2.1'); // -1.6
?>
