I found one typo in the topic optional chaining.

snippet:

let userAdmin = {  admin() {    alert("I am admin");  }};

In the below phrase:

Here, in both lines we first use the dot (userAdmin.admin) to get theadmin property, because we assume that theuserAdmin object exists, so it's safe read from it.

user should beuserAdmin cause the obj's name isuserAdmin notuser.

PS: Thank you for these great docs! A lot of information are well cleared.

Closes:#3499