Day 5 – Factorial of a Number in JavaScript: Recursion vs Loop

 🔥 JavaScript DSA Interview Series – Day 5

🧠 Problem: Find the factorial of a number using both loop and recursion

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✅ What is Factorial?

The factorial of a number n is the product of all positive integers less than or equal to n.

📌 n! = n × (n−1) × (n−2) × ... × 1

Example:

5! = 5 × 4 × 3 × 2 × 1 = 120

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📌 Iterative (Loop) Approach:

function factorialLoop(n) {

  let result = 1;

  for (let i = 2; i <= n; i++) {

    result *= i;

  }

  return result;

}

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📌 Recursive Approach:

function factorialRecursive(n) {

  if (n === 0 || n === 1) return 1;

  return n * factorialRecursive(n - 1);

}

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⚠️ Edge Case:

0! is 1

Negative numbers are not valid for factorial

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💡 Tips to Remember:

Use recursion only for small inputs (can cause stack overflow)

Loop is efficient and safe for interviews

Recursive solution shows understanding of function calls and base conditions

http://youtube.com/post/Ugkx1JuFK5mB2cSUAX8Yu0N6eFe8RuioUQ3Z?si=vN94FOnh01Dqq6A-