ios - What does it mean to "conform to protocol" in Objective-C/Xcode? -


i came across lot of "this thing conforms protocol" when working on tutorial ios apps. mean?

there 2 types of see:

  1. along lines of id <nsfetchedresultssectioninfo> sectioninfo = [self.fetchedresultscontroller sections] [section];

  2. by setting delegate self , having implement delegate method or similar that.

what difference , why doing that?

edit: https://stackoverflow.com/a/22794742/5020627

a protocol promise implement methods. conform protocol means both make promise , fulfill it.

your example of id <nsfetchedresultssectioninfo> "any kind of object implements required methods of protocol nsfetchedresultssectioninfo." (id in objective-c means "any kind of object.")

most setdelegate: methods require argument conform protocol. before assigning delegate, need make sure add promise (as part of @interface) , implement methods (to fulfill promise).


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