Addendum: Java Relevance-4

• In Objective C, the null (zero) object is known as nil.

• Because Objective C can send any message to any Object, an Object does not need to be of a particular subclass or to conform to a particular interface. So a single class can be a delegate and data source to any number of different objects.

• Because data source and delegate methods are declared in categories, you don't have to implement them.

• In case of Objective C, since memory management calls are given in the hands of developer, you need to be very careful while using alloc, copy, retain & release. One can easily introduce memory leaks in code, thats why supporting tools are provided in Xcode to verify such scenarios.