gmp_fact

(PHP 4 >= 4.0.4, PHP 5)

gmp_fact — Factorial

说明

resource gmp_fact ( int $a )

Calculates factorial (a!) of a .

参数

a

The factorial number.

It can be either a GMP number resource, or a numeric string given that it is possible to convert the latter to a number.

返回值

A GMP number resource.

范例

Example#1 gmp_fact() example


<?php
$fact1 = gmp_fact(5); // 5 * 4 * 3 * 2 * 1
echo gmp_strval($fact1) . "\n";

$fact2 = gmp_fact(50); // 50 * 49 * 48, ... etc
echo gmp_strval($fact2) . "\n";
?>

上例将输出：

120
30414093201713378043612608166064768844377641568960512000000000000