CODEWITHSUNDEEP
objective-c
johnbakers
johnbakers

Reputation: 24771

Why give a property both readonly and assign?

If assign is a setter, but a property is readonly, then it will not be doing any setting, so why use assign ?

I am getting this from the Apple docs on class extensions. In this page, I get why you'd want a public readonly property, then make it privately readwrite, but then why not omit the assign from the public @interface and just include it in the class extension only?

Upvotes: 1

Views: 138

Answers (2)

yuji
yuji

Reputation: 16725

If you declare a @property multiple times (typically because you declare a public readonly property in the header file, and a readwrite property in an anonymous category in your .m), the memory management schemes have to match.

So if you have this in your .m:

@property (assign, readwrite) NSObject *foo;

Then you need this in your header, and the assign is mandatory:

@property (assign, readonly) NSObject *foo;

Upvotes: 2

Alexander
Alexander

Reputation: 8147

If you leave just (nonatomic), the compiler will automatically set the second parameter to assign.

Upvotes: 0

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