Algorithmsbeginner

Factorial

📖 Usage Example

function factorial(n) {
  return n <= 1 ? 1 : n * factorial(n - 1);
}
factorial(5); // 120

Factorial uses recursion: multiply n by factorial(n-1) until the base case n<=1.

Factorial of a number n (written as n!) is the product of all positive integers less than or equal to n.

5! = 5 × 4 × 3 × 2 × 1 = 120
0! = 1 (by definition)

This is a classic example of recursion: the base case is n ≤ 1, and the recursive case is n × factorial(n-1).

function factorial(n: number): number {
  // Return n!
}

factorial(5) // 120
factorial(0) // 1

💡 Hints (3)

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