Day 5: Apply Transform Over Each Element in Array

Given an integer array arr and a mapping function fn, return a new array with a transformation applied to each element.

The returned array should be created such that returnedArray[i] = fn(arr[i], i).

Please solve it without the built-in Array.map method.

var map = function(arr, fn) {
    let result = [];
    fot(let i = 0; i < arr.length; i++) {
        result.push(fn(arr[i], i));
    }
    return result;
};

Example 1:
Input: arr = [1,2,3], fn = function plusone(n) { return n + 1; }
Output: [2,3,4]

Example 2:
Input: arr = [1,2,3], fn = function plusI(n, i) { return n + i; }
Output: [1,3,5]

Example 3:
Input: arr = [10,20,30], fn = function constant() { return 42; }
Output: [42,42,42]

雖然還是很簡單，不過開始變得有點囉說了

var map = function(arr, fn) {
    let result = [];
    for(let i = 0; i < arr.length; i++) {
        result.push(fn(arr[i], i));
    }
    return result;
};