PHP 5, PHP 7, PHP 8
bcpowmod - Raise an arbitrary precision number to another, reduced by a specified modulus

bcpowmod( string$num, string$exponent, string$modulus, [int|null$scale = null] ): string

Use the fast-exponentiation method to raise num to the power exponent with respect to the modulus modulus.



The base, as an integral string (i.e. the scale has to be zero).


The exponent, as an non-negative, integral string (i.e. the scale has to be zero).


The modulus, as an integral string (i.e. the scale has to be zero).


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 false if modulus is 0 or exponent is negative.



Because this method uses the modulus operation, numbers which are not positive integers may give unexpected results.


Version Description
8.0.0 scale is now nullable.

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Function bcpowmod:

BCMath Arbitrary Precision Mathematics Functions

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