The Day-One update for Nintendo Switch is here and adds the ability to add friends online. There are a few ways to add friends currently but the main one is via a 12-digit friend code. While this may be upsetting for some, there are some other ways including local connection, your “recently played with” list, or by connecting your friends list with Miitomo or Super Mario Run.
While it’s strange it’s not there at launch, Nintendo has confirmed that in the future people will be able to use their Nintendo Network ID to add friends. Until then however we’ll have to endure friend codes for the foreseeable future.