Oihana Php Core

factorial.php

Computes the factorial `n!` of a non-negative integer.


    
                    factorial(int $n) : int

factorial(0) is 1. The argument is capped at 20 because 21! exceeds PHP_INT_MAX and could no longer be represented exactly as an int.

throws

InvalidArgumentException

If $n is negative or greater than 20.

example

use function oihana\core\maths\factorial;

echo factorial( 0 ) ; // 1
echo factorial( 5 ) ; // 120
echo factorial( 10 ) ; // 3628800

author

Marc Alcaraz (ekameleon)

since

1.0.9

int —

The factorial of $n.