enhancedmath/lib/factorial.js

This package contains some enhanced mathematical operations

import { isNumber, isFraction } from './Helpers/index';
/**
 * Calculates the factorial of n
 * @param {number} n The amount
 * @returns {number} The factorial of n
 */
const factorial = (n) => {
    if (n < 0 || !isNumber(n) || isFraction(n))
        return undefined;
    if (n === 0 || n === 1)
        return BigInt(1);
    let result = BigInt(1);
    for (let i = n; i > 0; i--) {
        result *= BigInt(i);
    }
    return result.valueOf();
};
export default factorial;