Math Functions
PHP Manual

pow

Exponential expression

Description

number pow ( number $base , number $exp )

Returns base raised to the power of exp.

Note:

In PHP 5.6 onwards, you may prefer to use the ** operator.

Parameters

base

The base to use

exp

The exponent

Return Values

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.

Examples

Example #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(10, -1); // 0.1

echo pow(-1, 5.5); // PHP >=5.2.2: NAN
echo pow(-1, 5.5); // PHP <5.2.2: -NAN
?>

Notes

Note:

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

See Also

  • exp
  • sqrt
  • bcpow
  • gmp_pow