If you open up XCode (or probably another IDE) and type in __ you can see a lot of variables which starts with __. (in the auto complete box).
Why did the developers add the _s in there?
If you open up XCode (or probably another IDE) and type in __ you can see a lot of variables which starts with __. (in the auto complete box).
Why did the developers add the _s in there?
 
    
    