2724-sort-by.js

/**
 * 2724. Sort By
 * https://leetcode.com/problems/sort-by/
 * Difficulty: Easy
 *
 * Given an array arr and a function fn, return a sorted array sortedArr.
 * You can assume fn only returns numbers and those numbers determine the
 * sort order of sortedArr. sortedArr must be sorted in ascending order
 * by fn output.
 *
 * You may assume that fn will never duplicate numbers for a given array.
 */

/**
 * @param {Array} arr
 * @param {Function} fn
 * @return {Array}
 */
var sortBy = function(arr, fn) {
  return arr.sort((a, b) => fn(a) - fn(b));
};