🚀 Day 36/150 – Sum of Digits of a Number in Python

🚀 Day 36/150 – Sum of Digits of a Number in Python

The sum of digits means adding all digits of a number.

Examples:
1234 → 1 + 2 + 3 + 4 = 10
507 → 5 + 0 + 7 = 12

Let’s explore different ways to find sum of digits in Python 👇

🔹 Method 1 – Using while Loop

n = 1234 total = 0 while n > 0: digit = n % 10 total += digit n //= 10 print("Sum of digits:", total)

✅ Best method for logic building.

🔹 Method 2 – Taking User Input

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

temp = abs(n)

while temp > 0:
    total += temp % 10
    temp //= 10

print("Sum of digits:", total)

✅ Works for negative numbers too.

🔹 Method 3 – Using String + sum()

n = 1234 total = sum(int(i) for i in str(abs(n))) print("Sum of digits:", total)

✅ Shortest and cleanest method.

🔹 Method 4 – Using Recursion

def digit_sum(n): n = abs(n) if n == 0: return 0 return n % 10 + digit_sum(n // 10) print(digit_sum(1234))

✅ Great for recursion practice.

🎯 Output
Sum of digits: 10


🔑 Key Takeaways
Use % 10 to get the last digit.

Use // 10 to remove the last digit.

sum(int(i) for i in str(n)) is easiest.

Use abs(n) for negative numbers.