--- id: 595668ca4cfe1af2fb9818d4 title: Harshad or Niven series challengeType: 5 forumTopicId: 302281 dashedName: harshad-or-niven-series --- # --description-- The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits. For example, `42` is a Harshad number as `42` is divisible by `(4 + 2)` without remainder. Assume that the series is defined as the numbers in increasing order. # --instructions-- Implement a function to generate successive members of the Harshad sequence. Use it to return an array with ten members of the sequence, starting with first Harshad number greater than `n`. # --hints-- `isHarshadOrNiven` should be a function. ```js assert(typeof isHarshadOrNiven === 'function'); ``` `isHarshadOrNiven(10)` should return `[12, 18, 20, 21, 24, 27, 30, 36, 40, 42]` ```js assert.deepEqual(isHarshadOrNiven(10), [12, 18, 20, 21, 24, 27, 30, 36, 40, 42]); ``` `isHarshadOrNiven(400)` should return `[402, 405, 407, 408, 410, 414, 420, 423, 432, 440]` ```js assert.deepEqual(isHarshadOrNiven(400), [402, 405, 407, 408, 410, 414, 420, 423, 432, 440]); ``` `isHarshadOrNiven(1000)` should return `[1002, 1008, 1010, 1011, 1012, 1014, 1015, 1016, 1017, 1020]` ```js assert.deepEqual(isHarshadOrNiven(1000), [1002, 1008, 1010, 1011, 1012, 1014, 1015, 1016, 1017, 1020]); ``` # --seed-- ## --seed-contents-- ```js function isHarshadOrNiven(n) { const res = []; return res; } ``` # --solutions-- ```js function isHarshadOrNiven(n) { function isHarshad(num) { let s = 0; const nStr = num.toString(); for (let i = 0; i < nStr.length; ++i) { s += parseInt(nStr.charAt(i), 10); } return n % s === 0; } const res = []; let count = 0; while (count < 10) { n++; if (isHarshad(n)) { count++; res.push(n); } } return res; } ```