Factorial of a Number

JavaScript

Technical Specification

Given a non-negative integer n, return n! (n factorial).

Input/Output Samples

Input:5

Output:120

Input:0

Output:1

Optimal Logic Path

function factorial(n) {
  if (n === 0) return 1;
  return n * factorial(n - 1);
}

Architectural Deep-Dive

We use recursion with a base case. Each call multiplies n by factorial of n - 1.