Best way to store user data in local storage?

What is the best way to store user data in the local Storage?

Storing data with individual property

'userId': '234353-645657-75675675-5575'

'token': 'fgdfgfggergverger.t45regverrgt.he'

or include all the user data inside a big json object.

{
   'userId': '',
   'token': ''
}