🚀 Day 30/150 – Factorial of a Number in Python

 

🚀 Day 30/150 – Factorial of a Number in Python

The factorial of a number means multiplying all positive integers from 1 to n.
Example: 5! = 5 × 4 × 3 × 2 × 1 = 120

Let’s explore different ways to calculate factorial in Python 👇

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🔹 Method 1 – Using for Loop

n = 5
fact = 1

for i in range(1, n + 1):
    fact *= i

print("Factorial:", fact)

✅ Best and most common approach.

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🔹 Method 2 – Taking User Input

n = int(input("Enter a number: "))
fact = 1

for i in range(1, n + 1):
    fact *= i

print("Factorial:", fact)

✅ Useful for dynamic programs.

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🔹 Method 3 – Using while Loop

n = 5
fact = 1
i = 1

while i <= n:
    fact *= i
    i += 1

print("Factorial:", fact)

✅ Good for loop practice.

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🔹 Method 4 – Using Recursion

def factorial(n):
    if n == 0 or n == 1:
        return 1
    return n * factorial(n - 1)

print(factorial(5))

✅ Great for understanding recursive functions.

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📌 Example Output

For n = 5

120

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🎯 Best Method?

✔ for loop → easiest and efficient
✔ while loop → beginner practice
✔ recursion → advanced concept learning

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🔥 Follow for more Python basics in this 150 Days Python Challenge

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