Files
30-seconds-of-code/test/sortedIndexBy/sortedIndexBy.js
2018-01-26 20:13:34 +00:00

7 lines
276 B
JavaScript

const sortedIndexBy = (arr, n, fn) => {
const isDescending = fn(arr[0]) > fn(arr[arr.length - 1]);
const val = fn(n);
const index = arr.findIndex(el => (isDescending ? val >= fn(el) : val <= fn(el)));
return index === -1 ? arr.length : index;
};
module.exports = sortedIndexBy