NSString instance reports its class as NSCFString

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一整个雨季
一整个雨季 2020-12-03 10:44

My objective here is really simple -- I\'m trying to set an NSString to some test data, then return the class, which should be NSString. Here\'s my

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  • 2020-12-03 11:26

    NSString is really a container class for different types of string objects. Generally an NSString constructor does return an object that is actually of type NSCFString, which is a thin wrapper around the Core Foundation CFString struct.

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  • 2020-12-03 11:35

    NSString is a class cluster, along with other Foundation types such as NSNumber and NSArray:

    Class clusters are a design pattern that the Foundation framework makes extensive use of. Class clusters group a number of private, concrete subclasses under a public, abstract superclass. The grouping of classes in this way simplifies the publicly visible architecture of an object-oriented framework without reducing its functional richness. Class clusters are based on the Abstract Factory design pattern discussed in “Cocoa Design Patterns.”

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