bcmod
(PHP 4, PHP 5)
bcmod — Get modulus of an arbitrary precision number
Описание
string bcmod
( string $left_operand
, string $modulus
)
Get the modulus of the left_operand using modulus .
Список параметров
- left_operand
-
The left operand, as a string.
- modulus
-
The modulus, as a string.
Возвращаемые значения
Returns the modulus as a string, or NULL if modulus is 0.
Примеры
Пример #1 bcmod() example
<?php
echo bcmod('4', '2'); // 0
echo bcmod('2', '4'); // 2
?>
Коментарии
<?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 );
?>
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
?>