pow

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

powExponential expression

Опис

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

Returns num raised to the power of exponent.

Зауваження:

It is possible to use the ** operator instead.

Параметри

num

The base to use

exponent

The exponent

Значення, що повертаються

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.

Журнал змін

Версія Опис
8.4.0 Raising 0 to a negative exponent is now deprecated.

Приклади

Приклад #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
var_dump(pow(new GMP("3"), new GMP("2"))); // object(GMP)

echo pow(-1, 5.5); // NAN

?>

Примітки

Зауваження:

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

Прогляньте також

  • Exponentiation operator **
  • fpow() - Raise one number to the power of another, according to IEEE 754
  • exp() - Calculates the exponent of e
  • sqrt() - Square root
  • bcpow() - Raise an arbitrary precision number to another
  • gmp_pow() - Raise number into power

add a note

User Contributed Notes 2 notes

up
18
gilthansREMOVEME at gmail dot com
18 years ago
Note that pow(0, 0) equals to 1 although mathematically this is undefined.
up
2
Roman
4 years ago
If you use negative numbers, you need to use brackets for using with **

<?php

-1 ** 2; // -1

(-1) ** 2; // 1

?>
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