setItem() adds an item to the storage. Accepts a string as key, and a string as a value:

localStorage.setItem('username', 'flaviocopes')
localStorage.setItem('id', '123')

If you pass any value that’s not a string, it will be converted to string:

localStorage.setItem('test', 123) //stored as the '123' string
localStorage.setItem('test', { test: 1 }) //stored as "[object Object]"

Lessons in this unit:

0:	Introduction
1:	Session vs local storage
2:	▶︎ Setting an item
3:	Getting an item value
4:	Removing an item
5:	Clearing storage
6:	Storage size limits