What is '!!' doing?

[coordiy]

Hi. moeen.

I am looking at your code.
And, I am studying very much.

Please tell me about function checkAuth.

isAuthenticated: !! localStorage.getItem ('access_token')

What is this '!!' doing?

Thank you.

[Moeen]

!! is Coerces Object to boolean.

https://stackoverflow.com/questions/784929/what-is-the-not-not-operator-in-javascript