NSCoder, NSObject vs UIView

Question

When we implement (id)initWithCoder:(NSCoder *)decoder method in NSObject class, we need to call [super **init**], but in UIView somehow we need to call [super **initWithCoder:decoder**]. Why is there such a difference? The question is not a duplicate because it concerns protocols conformance to NSCoder in this particular case. There can well be other classes' situation similar to the one specified in the question.

Possible duplicate of [What is initWithCoder?](http://stackoverflow.com/questions/1829467/what-is-initwithcoder) — Petro Korienev, Nov 09 '15 at 19:44

score 3 · Accepted Answer · answered Nov 09 '15 at 19:47

You should call [super initWithCoder:decoder]; for any class that subclasses a class that already conforms to the NSCoding protocol.

In the case of a class that directly extends NSObject then of course you can't call [super initWithCoder:decoder]; because NSObject doesn't conform to NSCoder and therefore doesn't have an initWithCoder: you can call from the subclass. So you must call some other init method.

In the case of a custom view extending UIView, you do call it because UIView conforms to NSCoding.

NSCoder, NSObject vs UIView

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