'use strict';
function sum(number) {
const integer = parseInt(number);
if (isNaN(integer)) {
return `Wrong argument '${number}'. Argument must be integer.`;
}
const absInteger = Math.abs(integer);
if (absInteger <= 0) {
return 0;
}
const lastDigit = absInteger % 10;
return lastDigit + sum((absInteger - lastDigit) / 10);
}
console.log(sum('-257'));
English
Russian