Does it mutate 😱
Array.prototype.map
No mutation
Description
The map() method creates a new array with the results of calling a provided function on every element in this array.
Array.prototype.map ( callbackfn [ , thisArg ] )https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map
Example
var array1 = [1, 4, 9, 16];
// pass a function to map
const map1 = array1.map(x => x * 2);
console.log(map1);
// expected output: Array [2, 8, 18, 32]