Apply Transform Over Each Element in the Array

Apply Transform Over Each Element in the Array

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

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

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

Example 1:

Input: arr = [1,2,3], fn = function plusone(n) { return n + 1; }
Output: [2,3,4]
Explanation:
const newArray = map(arr, plusone); // [2,3,4]
The function increases each value in the array by one. 

Example 2:

Input: arr = [1,2,3], fn = function plusI(n, i) { return n + i; }
Output: [1,3,5]
Explanation: The function increases each value by the index it resides in.

Example 3:

Input: arr = [10,20,30], fn = function constant() { return 42; }
Output: [42,42,42]
Explanation: The function always returns 42.
/**
 * @param {number[]} arr
 * @param {Function} fn
 * @return {number[]}
 */
var map = function(arr, fn) {
    for(let i=0; i<arr.length; i++){
      arr[i] = fn(arr[i], i);
    }
    return arr;
};

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