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# pow

(PHP 4, PHP 5)

powExponential expression

### Description

number pow ( number \$base , number \$exp )

Returns base raised to the power of exp.

Warning

In PHP 4.0.6 and earlier pow() always returned a float, and did not issue warnings.

base

The base to use

exp

The exponent

### Return Values

base raised to the power of exp. If the result can be represented as integer it will be returned as type integer, else it will be returned as type float. If the power cannot be computed FALSE will be returned instead.

### Changelog

Version Description
Since 4.0.6 The function will now return integer results if possible, before this it always returned a float result. For older versions, you may receive a bogus result for complex numbers.
Since 4.2.0 PHP stops to emit a warning if the value can't be computed, it will now silently return FALSE only.

### Examples

Example #1 Some examples of pow()

``` <?phpvar_dump(pow(2, 8)); // int(256)echo pow(-1, 20); // 1echo pow(0, 0); // 1echo pow(-1, 5.5); // PHP >4.0.6  NANecho pow(-1, 5.5); // PHP <=4.0.6 1.#IND?> ```

• exp() - Calculates the exponent of e
• sqrt() - ریشه مربعی
• bcpow() - عددی با دقت دلخواه به توان عدد دیگر
• gmp_pow() - Raise number into power

### User Contributed Notes 3 notes

31
chris at ocportal dot com
5 years ago
``` Many notations use "^" as a power operator, but in PHP (and other C-based languages) that is actually the XOR operator. You need to use this 'pow' function, there is no power operator.i.e. 3^2 means "3 XOR 2" not "3 squared".It is particular confusing as when doing Pythagoras theorem in a 'closet points' algorithm using "^" you get results that look vaguely correct but with an error. ```
20
gilthansREMOVEME at gmail dot com
11 years ago
``` Note that pow(0, 0) equals to 1 although mathematically this is undefined. ```
scott at arciszewski dot me
4 years ago
``` As of PHP 5.6.0alpha2, there is now an exponentiation operator. If this is kept in the final release, it may be worth noting here.<?php// These two will be equivalent as of PHP 5.6.0\$x = \$y ** 2;\$x = pow(\$y, 2);?> ```