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Last updated: Tue, 19 Sep 2006


(PHP 3, PHP 4, PHP 5)

pow -- Exponential expression


number pow ( number base, number exp )

Returns base raised to the power of exp. If possible, this function will return an integer.

If the power cannot be computed, a warning will be issued, and pow() will return FALSE. Since PHP 4.2.0 pow() doesn't issue any warning.

Note: PHP cannot handle negative bases.

Example 1. Some examples of pow()


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

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



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

See also: exp(), sqrt(), bcpow(), and gmp_pow(),

Last updated: Tue, 19 Sep 2006