const sumAll = function (min, max) { if (!Number.isInteger(min) || !Number.isInteger(max)) return "ERROR"; if (min < 0 || max < 0) return "ERROR"; if (min > max) { const temp = min; min = max; max = temp; } // An alternative way to swap the values of min and max like above is to use the array destructuring syntax. // Here's an optional article on it: https://www.freecodecamp.org/news/array-destructuring-in-es6-30e398f21d10/ // if (min > max) [min, max] = [max, min]; let sum = 0; for (let i = min; i <= max; i++) { sum += i; } return sum; }; module.exports = sumAll;