js map in array not allowes code example

Example 1: js map constructor

let myMap = new Map([
  [1, 'one'], // [key, value]
  [2, 'two'],
  [3, 'three'],
]) // from MDN

Example 2: js map function

const exampleArray = ['aa','bbc','ccdd'];
console.log(exampleArray.map(a => a.length));
//Would print out [2,3,4]