🚀 Day 32/150 – Reverse a Number in Python

Reversing a number means changing the order of its digits from back to front.
Example: 12345 → 54321

Let’s explore different ways to reverse a number in Python 👇

🔹 Method 1 – Using while Loop

n = 12345
rev = 0

while n > 0:
    digit = n % 10
    rev = rev * 10 + digit
    n //= 10

print("Reversed Number:", rev)

✅ Best numeric method.

🔹 Method 2 – Taking User Input

n = int(input("Enter a number: "))
rev = 0

while n > 0:
    digit = n % 10
    rev = rev * 10 + digit
    n //= 10

print("Reversed Number:", rev)

✅ Useful for dynamic programs.

🔹 Method 3 – Using String Slicing

n = 12345
rev = str(n)[::-1]

print("Reversed Number:", rev)

✅ Shortest and easiest method.

🔹 Method 4 – Using Recursion

def reverse_num(n, rev=0): if n == 0: return rev return reverse_num(n // 10, rev * 10 + n % 10) print(reverse_num(12345))

✅ Great for learning recursion.

📌 Example Output

For 12345
o/p:54321

🎯 Best Method?

✔ while loop → best for logic building

✔ string slicing → fastest to write

✔ recursion → concept learning