The writing of Objective-c Init method

Thus, we arrive at the rules so all stylish objective-c programmers follow when writing initializers:if a class has SEv eral initializers, only one should does the real work. This is known as the
Designated initializer. All other initializers should call, either directly or indirectly, the designated
Initializer. The designated initializer'll call the superclass's designated initializer before its
Instance variables. If the designated initializer of your class has a different name than the designated initializer of
Its superclass, your must override the superclass ' designated initializer so it calls the new
Designated initializer. If you have several initializers, clearly document which are the designated in the header.

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