phaser/src/math/Factorial.js
2019-01-15 16:20:22 +00:00

34 lines
695 B
JavaScript

/**
* @author Richard Davey <rich@photonstorm.com>
* @copyright 2019 Photon Storm Ltd.
* @license {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/
/**
* Calculates the factorial of a given number for integer values greater than 0.
*
* @function Phaser.Math.Factorial
* @since 3.0.0
*
* @param {number} value - A positive integer to calculate the factorial of.
*
* @return {number} The factorial of the given number.
*/
var Factorial = function (value)
{
if (value === 0)
{
return 1;
}
var res = value;
while (--value)
{
res *= value;
}
return res;
};
module.exports = Factorial;