bcpowmod
(PHP 5, PHP 7)
bcpowmod — Raise an arbitrary precision number to another, reduced by a specified modulus
Description
string bcpowmod ( string $base , string $exponent , string $modulus [, int $scale = 0 ] ) Use the fast-exponentiation method to raise base to the power exponent with respect to the modulus modulus.
Parameters
base
The base, as an integral string (i.e. the scale has to be zero).
exponent
The exponent, as an non-negative, integral string (i.e. the scale has to be zero).
modulus
The modulus, as an integral string (i.e. the scale has to be zero).
`scale` This optional parameter is used to set the number of digits after the decimal place in the result. If omitted, it will default to the scale set globally with the bcscale() function, or fallback to 0 if this has not been set.
Return Values
Returns the result as a string, or NULL if modulus is 0 or exponent is negative.
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() 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() - Raise an arbitrary precision number to another
- bcmod() - Get modulus of an arbitrary precision number
← bcpow
bcscale →
? 1997–2017 The PHP Documentation GroupLicensed under the Creative Commons Attribution License v3.0 or later.
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