How can I check if a localstorage variable is null or undefined?

Question

I have this code:

var sideBar = localStorage.getItem(\'Sidebar\');

I want to check if sideBar is defined and not null in an if statement. I am

Answer 1

best practice for checking if a variable is defined and not null:

if (typeof sideBar !== 'undefined' && sideBar !== null)

edited realized you're not checking if something is undefined, you're checking that it's defined, so edited again to answer your request more accurately