Ios technical questions, ios technical questions

Ios technical questions, ios technical questions

1. Difference between shallow copy and deep copy?

The copy-only address does not copy the object pointed to by the address.

Deep copy Copy address and point to the new object to be copied

2. What is advantage of categories? What is difference between implementing a category and inheritance?

 

Categories: modify the original functions without affecting or modifying the original category or module, and add new functions.

3. Difference between categories and extensions?

 

Categories: modify the original functions without affecting or modifying the original category or module, and add new functions.

4. Difference between protocol in objective c and interfaces in java?

 

I think they are the same protocol. They can be inherited from interfaces.

Interfaces in java is protocol in objective-c.

In java, the class in objective-c is the interface

5. What are KVO and KVC?