2724. Sort By
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. sortedArray must be sorted in ascending order by fn output.
You may assume that fn will never duplicate numbers for a given array.
Example 1:
Example 2:
Example 3:
Constraints:
- arr is a valid JSON array
- fn is a function that returns a number
- 1 < = a r r . l e n g t h < = 5 ∗ 1 0 5 1 <= arr.length <= 5 * 10^5 1<=arr.length<=5∗105
From: LeetCode
Link: 2724. Sort By
Solution:
Ideas：
We use Array.sort() to sort the array. We pass a comparator function that subtracts the result of fn(a) from fn(b). This will sort in ascending order since subtracting smaller from larger gives a negative number.
Code:
/**
* @param {Array} arr
* @param {Function} fn
* @return {Array}
*/
var sortBy = function(arr, fn) {
return arr.sort((a, b) => fn(a) - fn(b));
};