Exercises
1. Implement a copy method for the AddressBook
class according to the NSCopying
protocol. Would it make sense to also implement a mutableCopy
method? Why or why not? Also, think about what happens if someone uses the setter method for the book property in the AddressBook
class. Who should own the address book that gets passed as the argument to the setter? How can you fix this?
2. Modify the Rectangle
and XYPoint
classes defined in Chapter 8 to conform to the <NSCopying>
protocol. Add a copyWithZone
: method to both classes. Make sure that the Rectangle
copies its XYPoint
member origin using the XYPoint
’s copy method. Does it make sense to implement both mutable and immutable copies for these classes? Explain.
3. Create an NSDictionary ...
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