pow

(PHP 4, PHP 5)

pow — Exponential expression

Açıklama

number pow ( number $base , number $exp )

Returns base raised to the power of exp.

Değiştirgeler

base: The base to use
exp: The exponent

Dönen Değerler

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

Sürüm Bilgisi

Sürüm:	Açıklama
4.2.0	No warning is emitted on errors, even if the value can't be computed.
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.

Örnekler

Örnek 1 Some examples of pow()


<?php

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

echo pow(-1, 5.5); // PHP >4.0.6  NAN
echo pow(-1, 5.5); // PHP <=4.0.6 1.#IND
?>

Notlar

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

Ayrıca Bakınız

exp() - Calculates the exponent of e
sqrt() - Square root
bcpow() - Keyfi duyarlıklı sayılar için üs alma işlemi yapar
gmp_pow() - Raise number into power

add a note User Contributed Notes pow - [2 notes]

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chris at ocportal dot com ¶

1 year 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.

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gilthansREMOVEME at gmail dot com ¶

6 years ago


Note that pow(0, 0) equals to 1 although mathematically this is undefined.

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