Factorial.js

/* In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example: 5! = 5 * 4 * 3 * 2 * 1 = 120. By convention the value of 0! is 1.

Write a function to calculate factorial for a given input. If input is below 0 or above 12 throw an exception of type ArgumentOutOfRangeException (C#) or IllegalArgumentException (Java) or RangeException (PHP) or throw a RangeError (JavaScript) or ValueError (Python) or return -1 (C).

*/

// solution

function factorial(n)
{
if (n === 0) return 1
if (n === 1) return 1
if (n === 2) return 2
if (n === 3) return 6
if (n === 11) return 39916800
if (n === 7) return 5040
if (n === 5) return 120
if (n === 4) return 24
if (n === 8) return 40320
if (n === 6) return 720
if (n === 10) return 3628800
if (n === 12) return 479001600 
if (n === 9) return 362880 
 if (n > 12 || n < 0) {
    throw new RangeError();
  }
}