Question

Write a program to find the sum of digits of an integer number, input by the user.

Answer 1

The program can be written in two ways.

1. The number entered by the user can be converted to an integer and then by using the 'modulus' and 'floor' operators it can be added digit by digit to a variable 'sum'.
2. The number is iterated as a string and just before adding it to the 'sum' variable, the character is converted to the integer data type.

Program 1:
#Program to find sum of digits of an integer number
#Initializing the sum to zero
sum = 0
#Getting user input
n = int(input("Enter the number: "))
# looping through each digit of the number
# Modulo by 10 will give the first digit and
# floor operator decreases the digit 1 by 1
while n > 0:
    digit = n % 10
    sum = sum + digit
    n = n//10
# Printing the sum
print("The sum of digits of the number is",sum)

OUTPUT:
Enter the number: 23
The sum of digits of the number is 5

Program 2:
​​#Initializing the sum to zero
sum = 0
#Asking the user for input and storing it as a string
n = input("Enter the number: ")
#looping through each digit of the string
#Converting it to int and then adding it to the sum
for i in n:
    sum = sum + int(i)
   
# Printing the sum
print("The sum of digits of the number is",sum)

OUTPUT:
Enter the number: 44
The sum of digits of the number is 8.