can i use Optional Chaining code example

Example 1: optional chaining in javascript

let myMap = new Map();
myMap.set("foo", {name: "baz", desc: "inga"});

let nameBar = myMap.get("bar")?.name;

Example 2: optional chaining

const array = [1,2,3,4,5];
let arrItem = array?.[4]; 

console.log(arrItem); /// 5