300 friend cap, too.
The day one patch that activates the Nintendo Switch's online features has gone live for those who have received the new hybrid console early, and it's answered one of the unanswered questions about the system - the Nintendo Switch is using friend codes (thanks, Eurogamer).
When you click on your user profile, you'll be able to see your friend code in the bottom corner. This is the code that friends will enter if they want to send you a friend request. You can also search for local users and search for users you've played with, but unless you've played with someone before or are physically in the same room with them, you can find and add them as friends that way as well.
More than that, however, over on the Japanese website, Nintendo suggests that the system will only allow up to 300 friends. There is currently no option for adding friends from social media accounts.