004 — 2635. Apply Transform Over Each Element in Array.js

/**
 * @param {number[]} arr
 * @param {Function} fn
 * @return {number[]}
 */
var map = function(arr, fn) {
    const ans = []

    for (const i in arr){
        ans.push(fn(arr[i], Number(i)))
    }

    return ans;
};