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pow

(PHP 4, PHP 5, PHP 7, PHP 8)

pow — Exponential expression

Description

pow(mixed $num, mixed $exponent): int|float|object

Returns num raised to the power of exponent.

Note:

It is possible to use the ** operator instead.

Parameters

num

The base to use

exponent

The exponent

Return Values

num raised to the power of exponent. If both arguments are non-negative integers and the result can be represented as an integer, the result will be returned with int type, otherwise it will be returned as a float.

PHP-Extensions may override the behaviour of this operation and make it return an object.

Changelog

Version Description
8.4.0 Raising 0 to a negative exponent is now deprecated.

Examples

Example #1 Some examples of pow()

<?php

var_dump(pow(2, 8)); // int(256)
echo pow(-1, 20), PHP_EOL; // 1
echo pow(0, 0), PHP_EOL; // 1
echo pow(10, -1), PHP_EOL; // 0.1

echo pow(-1, 5.5), PHP_EOL; // NAN
?>

Example #2 Examples of pow() With GMP Extension Object

<?php
var_dump(pow(new GMP("3"), new GMP("2"))); // object(GMP)
?>

Notes

Note:

This function will convert all input to a number, even non-scalar values, which could lead to weird results.

See Also