pi

(PHP 3, PHP 4 >= 4.0.0)

pi -- Get value of pi

Description

float pi ( void)

Returns an approximation of pi. The returned float has a precision based on the precision directive in php.ini, which defaults to 14. Also, you can use the M_PI constant which yields identical results to pi().

echo pi(); // 3.1415926535898
echo M_PI; // 3.1415926535898