How to make an immutable readonly property in the header file (.h), a mutable readwrite property in implementaion (.m)

Question

I have an object that holds a dictionary JSONData. From the header file, and to the other classes that\'ll access it, I want this property to only be read-only

Answer 1

You need a separate private mutable variable in your implementation. You can override the getter to return an immutable object.

@interface MyObject () {
  NSMutableDictionary *_mutableJSONData;
}
@end

@implementation MyObject 

// ...

-(NSDictionary *)JSONData {
   return [NSDictionary dictionaryWithDictionary:_mutableJSONData];
}

// ...
@end

No need to implement the setter, as it is readonly.