Scala function: Calculate the sum of digits in a number

Last update on February 06 2025 12:56:20 (UTC/GMT +8 hours)

Write a Scala function to calculate the sum of digits in a given number.

Before you start!

To solve this problem, you should have a basic understanding of:

• Scala functions and how to define them.
• Loops (e.g., while loops) for iteration.
• Basic arithmetic operations, especially modulus (%) and division (/).
• How to extract digits from a number using modulus and integer division.

Try before looking at the solution!

Think about how you can break down a number into its individual digits:

• What operation gives you the last digit of a number?
• How do you remove the last digit from a number?
• How can you repeat this process until all digits are processed?
• What variable should you use to store the sum of the digits?

Try writing a small program to extract digits from a number before attempting the full solution!

Sample Solution:

Scala Code:

object DigitSumCalculator {
  def sumOfDigits(n: Int): Int = {
    var num = n
    var sum = 0

    while (num != 0) {
      val digit = num % 10
      sum += digit
      num /= 10
    }

    sum
  }

  def main(args: Array[String]): Unit = {
    val number = 12345678
    val sum = sumOfDigits(number)
    println(s"The sum of digits in $number is: $sum")
  }
}

Sample Output:

The sum of digits in 12345678 is: 36

Scala Code Editor :

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