bcpow
(PHP 4, PHP 5, PHP 7, PHP 8)
bcpow — Raise an arbitrary precision number to another
Description
$num, string $exponent, ?int $scale = null): string
Raise num to the power
exponent.
Parameters
-
num -
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
-2147483648to2147483647. -
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
0if this has not been set.
Return Values
Returns the result as a string.
Changelog
| Version | Description |
|---|---|
| 7.3.0 | bcpow() 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
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"
?>
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
