Sort By.JS

// 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.

 

// Example 1:

// Input: arr = [5, 4, 1, 2, 3], fn = (x) => x
// Output: [1, 2, 3, 4, 5]
// Explanation: fn simply returns the number passed to it so the array is sorted in ascending order.


// code

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