call a function on each item return from a map code example

Example 1: javascript map array

const 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]

Example 2: array mdn map

let new_array = arr.map(function callback( currentValue[, index[, array]]) {
    // return element for new_array
}[, thisArg])