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 a bit confused I know there’s a: sideBar == undefined and sideBar != null

but is there a good way for me to do this test for both of these inside an if:

if (??) 

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