Question

I have the following code inside a method:

UIImageView* imageBlk = self.image;
self.finishBlock = ^{
    imageBlk.hidden = YES;
}

Under ARC, will self get retained by the block because image is a property of self? Who owns imageBlk? Self?

Answer 1

Will self be retained by the block? No it will not. The imageBlk variable is not an instance variable so the block has no need to retain self. There is no worry of a retain cycle in your posted code.

Who owns imageBlk? imageBlk is a stack variable. The block will retain the variable. ARC takes care of this retention and well as properly releasing it when appropriate.

Who owns self? We can’t answer that from this code. Who ever has allocated the object will own it. Who ever has retained it also owns it.