BCPOWMOD(3) 1 BCPOWMOD(3)
bcpowmod - Raise an arbitrary precision number to another, reduced by a specified modulus
SYNOPSIS
string bcpowmod (string $left_operand, string $right_operand, string $modulus, [int $scale = int])
DESCRIPTION
Use the fast-exponentiation method to raise $left_operand to the power $right_operand with respect to the modulus $modulus.
PARAMETERS
o $left_operand
- The left operand, as a string.
o $right_operand
- The right operand, as a string.
o $modulus
- The modulus, as a string.
o $
scale -This optional parameter is used to set the number of digits after the decimal place in the result. You can also set the
global default scale for all functions by using bcscale(3).
RETURN VALUES
Returns the result as a string, or NULL if $modulus is 0.
NOTES
Note
Because this method uses the modulus operation, numbers which are not positive integers may give unexpected results.
EXAMPLES
The following two statements are functionally identical. The bcpowmod(3) version however, executes in less time and can accept larger
parameters.
<?php
$a = bcpowmod($x, $y, $mod);
$b = bcmod(bcpow($x, $y), $mod);
// $a and $b are equal to each other.
?>
SEE ALSO
bcpow(3), bcmod(3).
PHP Documentation Group BCPOWMOD(3)
