PHP5中文手册·Raise an arbitrary precision number to another, reduced by a specified modulus -- 追寻梦想＞编程乐园＞PHP 编程

说明

string bcpowmod ( string $left_operand , string $right_operand , string $modulus [, int $scale ] )

Use the fast-exponentiation method to raise left_operand to the power right_operand with respect to the modulus modulus .

参数

left_operand: The left operand, as a string.
right_operand: The right operand, as a string.
modulus: The modulus, as a string.
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().

返回值

Returns the result as a string, or NULL if modulus is 0.

注释

Note: Because this method uses the modulus operation, non-natural numbers may give unexpected results. A natural number is any positive non-zero integer.

范例

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.

?>


	PHP5中文手册 bcpow bcscale BC math PHP Manual bcpowmod (PHP 5) bcpowmod — Raise an arbitrary precision number to another, reduced by a specified modulus 说明 string bcpowmod ( string `$left_operand` , string `$right_operand` , string `$modulus` [, int `$scale` ] ) Use the fast-exponentiation method to raise `left_operand` to the power `right_operand` with respect to the modulus `modulus` . 参数 `left_operand` The left operand, as a string. `right_operand` The right operand, as a string. `modulus` The modulus, as a string. `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(). 返回值 Returns the result as a string, or `NULL` if `modulus` is 0. 注释 Note: Because this method uses the modulus operation, non-natural numbers may give unexpected results. A natural number is any positive non-zero integer. 范例 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. ?>` 参见 bcpow() bcmod() bcpow bcscale BC math PHP Manual

bcpowmod

说明

参数

返回值

注释

范例

参见