Arrays.map

The Array.prototype.map method creates a new array populated with the results of calling a provided function on every element in the calling array.

code

Array.prototype.myMap = function (callbackFn) {
  var arr = [];
  for (var i = 0; i < this.length; i++) {
    arr.push(callbackFn(this[i], i, this));
  }
  return arr;
};

Explanation:

1. Initialization:

• var arr = []; initializes a new empty array to store the results.

2. Loop through the array:

• for (var i = 0; i < this.length; i++) { ... } loops through each element of the array.

3. Callback Execution:

• callbackFn(this[i], i, this) calls the provided function callbackFn with three arguments: - this[i]: the current element.
• i: the index of the current element. this: the array being processed.

4. Push Results:

• arr.push(callbackFn(this[i], i, this)); stores the result of callbackFn in the new array.

5. Return New Array:

• return arr; returns the new array with the transformed elements.