Sum of Digits in Kotlin (Beginner-Friendly)
• kotlinbeginnersalgorithmsnumbersbasic-problems
fun sumOfDigits(n: Int): Int {
require(n >= 0) { "Input must be a non-negative integer." }
return n.toString().map { it - '0' }.sum()
}
fun main() {
println("Enter a non-negative integer:")
val input = readLine()
if (input.isNullOrBlank()) {
println("Error: No input provided.")
return
}
val number = input.toIntOrNull()
if (number == null) {
println("Error: Input is not a valid integer.")
return
}
if (number < 0) {
println("Error: Please enter a non-negative integer.")
return
}
val result = sumOfDigits(number)
println("Sum of digits: $result")
}
/*
Sample Output:
Enter a non-negative integer:
12345
Sum of digits: 15
*/

