Set Custom Cookie

[hackthedev]

Hi i'd like to use Socket.io to set a custom cookie.

I want to create a cookie named (example) "theme" with values like "dark", "default".

My plan is to store stuff like the style that should be loaded upon next visit and the duration would be as long as possible. I've once done this but it was with PHP sadly.

Any help? Thx in advance

PS: I've seen some examples but i dont really understand them they look very complicated