(PHP 4, PHP 5, PHP 7)
bcpow — 任意精度数字的成方
$left_operand
, string $right_operand
[, int $scale
] )
左操作数的右操作数次方运算.
left_operand字符串类型的左操作数.
right_operand字符串类型的右操作数.
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。
返回结果为字符串类型.
Example #1 bcpow() 示例
<?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"
?>