The JavaScript map function is a powerful method available on arrays that allows you to transform each element in the array and create a new array with the applied transformations. It's a part of the Array object and is used for creating a new array from an existing one, without modifying the original array.

Code Example

Here's a simple example of how the map function can be used to square each number in an array:

In this example, map takes a callback function that gets called for each element of the numbers array. The return value of the callback function is then used to create the new array, squares.

Explanation and Discussion

The map function does not execute the function for array elements without values. It also does not mutate the array on which it is called (although the callback function can do so if it wishes).