objective-C how to declare private property for category?

Question

I'm new to objective-C, so apologies if this is repeated somewhere. I have a category(?) that is something like:

inside SomeClass.h:

@interface SomeClass (SomeCategory) <SomeDelegate>
@property (nonatomic, retain) id somePublicProperty;
@property (nonatomic, retain) id someProperty; // <-- i want to move this to "private"
@end

and now in my SomeClass.m, all i have is:

@implementation SomeClass (SomeCategory)

// dynamic setters/getters here for someProperty.

@end

I think the someProperty is public. how do i make this "private"? (in other words, how do i syntactically put this in the .m file? i tried to use

@interface SomeClass (SomeCategory) {
    @property (nonatomic, retain) somePrivateProperty;
} 
@end

but it just complains that i have duplicate definition of the category. how do i do this correctly?

Answer 1

Just add the category definition in the .m file OUTSIDE the implementation block

Like so:

@interface MyClass (MyCategory)
@property (assign) BOOL myPrivateProperty;
@end

@implementation MyClass
...
@end