在线文档教程
PHP
数学 | Mathematics

bcpow

bcpow

(PHP 4, PHP 5, PHP 7)

bcpow — Raise an arbitrary precision number to another

Description

string bcpow ( string $base , string $exponent [, int $scale = 0 ] )

Raise base to the power exponent.

Parameters

base

The base, as a string.

exponent

The exponent, as a string. If the exponent is non-integral, it is truncated. The valid range of the exponent is platform specific, but is at least -2147483648 to 2147483647.

`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.

Changelog

VersionDescription
7.3.0bcpow() now returns numbers with the requested scale. Formerly, the returned numbers may have omitted trailing decimal zeroes.

Examples

Example #1 bcpow() example

<?php echo bcpow('4.2', '3', 2 // 74.08 ?>

Notes

Note: Before PHP 7.3.0 bcpow() may return a result with fewer digits after the decimal point than the scale parameter would indicate. This only occurs when the result doesn't require all of the precision allowed by the scale. For example: Example #2 bcpow() scale example <?php echo bcpow('5', '2', 2     // prints "25", not "25.00" ?>

See Also

  • bcpowmod() - Raise an arbitrary precision number to another, reduced by a specified modulus

  • bcsqrt() - Get the square root of an arbitrary precision number

← bcmul

bcpowmod →

© 1997–2017 The PHP Documentation Group

Licensed under the Creative Commons Attribution License v3.0 or later.

https://secure.php.net/manual/en/function.bcpow.php