What do the plus and minus signs mean in Objective-C next to a method?

+ is for a class method and – is for an instance method. E.g. // Not actually Apple’s code. @interface NSArray : NSObject { } + (NSArray *)array; – (id)objectAtIndex:(NSUInteger)index; @end // somewhere else: id myArray = [NSArray array]; // see how the message is sent to NSArray? id obj = [myArray objectAtIndex:4]; // here … Read more