FACTORIAL

Question : Write a program to find a Factorial of a Number.

The factorial function (symbol: !) says to multiply all whole numbers from our chosen number down to 1.

Examples :

• 4! = 4 * 3 * 2 * 1 = 24
• 7! = 7 * 6 * 5 * 4 * 3 * 2 * 1 = 5040
• 1! = 1

Method 1

function factorial(n) {
  let res = 1;
  if (n == 0 || n == 1) return n;
  else {
    for (let i = n; i >= 1; i--) {
      res *= i;
    }
  }

  return res;
}

console.log(factorial(5)); //Prints: 120