(PHP 4, PHP 5)
bcpow — Raise an arbitrary precision number to another
$left_operand
, string $right_operand
[, int $scale
] )
Raise left_operand to the power
right_operand.
left_operandThe left operand, as a string.
right_operandThe right operand, as a string.
scale此可选参数用于设置结果中小数点后的小数位数。也可通过使用 bcscale() 来设置全局默认的小数位数，用于所有函数。
Returns the result as a string.
Example #1 bcpow() example
<?php
echo bcpow('4.2', '3', 2); // 74.08
?>
Note:
bcpow() may return a result with fewer digits after the decimal point than the
scaleparameter would indicate. This only occurs when the result doesn't require all of the precision allowed by thescale. For example:Example #2 bcpow() scale example
<?php
echo bcpow('5', '2', 2); // prints "25", not "25.00"
?>