JavaScript: Calculate the factorial of a number

Last update on August 19 2022 21:50:50 (UTC/GMT +8 hours)

JavaScript fundamental (ES6 Syntax): Exercise-238 with Solution

Write a JavaScript program to calculate 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.

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>Calculate the factorial of a number</title>
</head>
<body>

</body>
</html>

JavaScript Code:

//#Source https://bit.ly/2neWfJ2 
const factorial = n =>
  n < 0
    ? (() => {
        throw new TypeError('Negative numbers are not allowed!');
      })()
    : n <= 1
      ? 1
      : n * factorial(n - 1);

console.log(factorial(1));
console.log(factorial(5));
console.log(factorial(7));

Sample Output: