pi()

pi() — Get value of pi.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

What it does

Returns an approximation of pi. Also, you can use the M_PI constant which yields identical results to pi().

Signature

pi(): float

Parameters

This function takes no parameters.

Return value

The value of pi as float.

Example

A runnable snippet:

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

All PHP 8.5 built-in functions

Reference card built from the PHP manual page pi() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.