Hi, my native iOS app requires user to be logged in to use its features. I implemented a clean and neat sign it with apple. Is it even worth bothering implementing other signs in, like fb, or google? This message is for people using apple sign in as well as other sign in methods, if you could share your rough % of sign in distribution. Thanks, Ald

This code is invalid: func name1() {   func nest1() - Int {     print("nest1")     return 3   }       func nest1() - String {     print("nest2")     return "nest1"   } } both nest1 function can't coexist. But they have a different signature: one is returning an int and the other a string. Aren't functions with different signatures, supposed to be able to coexist?

class One {   func sayOne() {     print("from inside One")   }       class Second {     func saySecond() {       print("from inside second")     }   } } One.Second().saySecond() Why can I access Second class without instantiating One() with parenthesis, when I can't access member function and variables without instantiation with ()?

I'm building a quiz system and i'm not sure how to structure it on the database side.Let's say the quiz system is for trees species. User will be presented a tree picture (an entry), and will have to select the correct species among a list of 6 (5 random, 1 correct). There are 250 species in the quiz.The two main problems I need to solve:1) User should never see again the same tree entry.2) Owner of a tree entry, must be able to see stats of all the votes on his entry: so he will see number of votes, per tree species, entered by other users on his entry. Because users will make mistakes on votes, owner of entry will see stats of those mistakes and which incorrect species his entry was mistaken for.An easy way to do it, would be to create several tables:Users tableTrees table: With foreign key to User table. This is entries users will have to vote on. One user can create one entry.Votes tables: With foreign key to both user table and tree table. This table will hold each and every vote, including tree species name selected by the user on that vote.So to solve my problem:1) Prevent user to see same entry again: Before fetching "Trees" to present new trees to vote on, run a first query to get all "Votes" for that user to exclude "Trees" the user has already voted on.2) See stats of votes on own entry: Fetch all votes pointing to own entry, then compute stats by tree species selected.This approach is straightforward, but what bothers me is having to create an entry for each and every vote. There can be lots of it. I'm inexperienced with db design, so not sure if this could be a problem or not.Would this alternative way be better:1) To keep track of already voted entries: On a single record (per user), hold in a single field, ALL voted ids, so instead of running a query to prefetch each votes entries, simply get them from a single field. Not sure if this is doable, and what is the limit size of a single field that could potentially hold thousands of votes which are in fact ids of entries voted on.2) So owner of an entry can view that entry statistics: On EACH tree entry, create 250 columns, one per tree species, and increment an INT on each depending on what is voted on. So to get stats of each entry, it would only be a matter of fetching one single record and do the computation client side.What would be the best approach? Is there one that should be avoided?