30-seconds-of-code/snippets/factorial.md

title, tags, expertise, cover, firstSeen, lastUpdated

title	tags	expertise	cover	firstSeen	lastUpdated
Factorial of number	math,algorithm,recursion	beginner	blog_images/flower-vase.jpg	2017-12-07T14:41:33+02:00	2020-12-28T13:49:24+02:00

Calculates the factorial of a number.

• Use recursion.
• If n is less than or equal to 1, return 1.
• Otherwise, return the product of n and the factorial of n - 1.
• Throw a TypeError if n is a negative number.

const factorial = n =>
  n < 0
    ? (() => {
        throw new TypeError('Negative numbers are not allowed!');
      })()
    : n <= 1
    ? 1
    : n * factorial(n - 1);

factorial(6); // 720