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C++ How To Calculate the Sum of Digits

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Calculate the Sum of Digits

Add up all the digits of a number by taking one digit at a time:

Example

int number = 1234;
int sum = 0;

while (number > 0) {
  sum += number % 10;
  number /= 10;
}

cout << "Sum of digits: " << sum;

Try it Yourself »

Explanation:
number % 10 gives the last digit, which is added to sum.
number /= 10 removes the last digit.
1 + 2 + 3 + 4 is 10.

Related Pages

C++ While Loop Tutorial

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