bcmod

(PHP 4, PHP 5, PHP 7)

bcmod — 对一个任意精度数字取模

说明

bcmod ( string $left_operand , string $modulus ) : string

对左操作数使用系数取模

参数

left_operand

字符串类型的左操作数

modulus

字符串类型系数

返回值

返回字符串类型取模后结果，如果系数为0则返回null

范例

Example #1 bcmod() example

<?php
echo bcmod('4', '2'); // 0
echo bcmod('2', '4'); // 2
?>

参见

  • bcdiv() - 2个任意精度的数字除法计算

User Contributed Notes

drahoszdenek at gmail dot com 01-Feb-2013 04:44
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
?>
lauris at night dot lt 23-Dec-2003 08:04
<?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 );
?>