Preface: Welcome everyone to comment, give the correct answer1, object-c have multiple inheritance? What's the substitute for nothing? No, protocol is the principal agent.
2. Does object-c have a private method? What about private variables? No, there is.
3, #import和 the difference of # include, what @class represent? #import prevents duplicate references, #include cannot, @class the predecessor declares a class. 4, object-c memory management? Reference counter. 5. Why are many built-in classes, such as Tableviewcontroller's delegate properties assign not retain? Prevent circular references. 6. When defining attributes, what is the use of copy, assign, retain? Copy: Copies the object. Assign: Pass-through value, generally used for the underlying type. Retain: Pass address, reference counter plus one. 7. When was the object being release? The reference counter is 0.8, does iOS have garbage collection? Didn't. 9, the reuse mechanism of TableView? Reuse tags. 10, when the Viewcontroller Loadview, Viewdidload, viewdidunload are called, when the custom Viewcontroller in these functions should do what work? Called when view is nil when call Loadview,view completes the load call when Viewdidload,view is released viewdidunload.11, When was the didreceivememorywarning of Viewcontroller called? What is the default action? Memory exceeds threshold, try to release view.12, enumerate the implementation of the common multi-threaded in cocoa, and talk about several ways to solve multi-thread security, generally what will use multi-threading? NSTHREAD,GCD and so on. Try to implement multithreading instead of manually calling Nsthread by using the top-level split-up method. 13, how to understand MVC, how is MVC implemented in cocoa? Model--view--controller.
14, delegate and notification difference, respectively, under what circumstances use?
both are used to deliver messages, except that delegate is one-to- many, andnotification is one-to-much.
15, self. What's the difference with self? 16. What does the ID and nil mean? The ID equals Void*,nil is an empty object. 17, memory management autorelease, retain, copy, assign set method and meaning? 18, the role of the category? 19, Entrust (for example) 20, Retaincount? 21. In OBJC, the opposite of Alloc semantics is dealloc or release? The opposite approach to retain semantics is dealloc or release, why? How do I use the Dealloc or release method to pair with Alloc? 22, in the method of an object: Self.name = "Object"; and name = "Object" What is the difference?
23. What's wrong with this code: @implementation person-(void) Setage: (int) newage {self.age = NewAge;}
24. After each line of code executes, the person object's retain count is how many person *person = [[Person alloc] init]; [Person retain]; [Person release]; [Person release];
25. When was the object of Autorelease being release?
26. What is wrong with this code, how to modify for (int i = 0; i < Somelargenumber; i++) {NSString *string = @ "ABC"; string = [String lowercasestring ];string = [string stringbyappendingstring:@ "XYZ"]; NSLog (@ "%@", string);}
27. What is the relationship between Autorelease and the garbage collection mechanism (GC)?
28. What is notification?
29. When to use delegate, when to use notification?
30, what is KVC and kvo?
31. What is the difference between notification and KVO?
32, KVO in the OBJC how to achieve?
33. What are the benefits of threading comprehension?
34, examine the understanding of @interface and @propety
35. The type conversion in Objective-c is divided into which categories
36. Polymorphic Understanding
Questions for iOS base plane
