 So you need to raise your hands and I'm randomly going to ask somebody so what it means is If you have a Class and you want to object of a class and you want to downcast it to a subclass What is the operator you are going to use? Yeah, that's correct Need a browser Yeah So the answer is basically you use you know whatever object it is, right? object one As a type, you know, whatever the subclass name You can use optional or I think not even if you don't use You just use age We need optional Which if you put optional is basically answers that if this fails then this Object is nil and which you can handle it on This is a dictionary declaration of a specific type And you need to support something here What is the thing that you need to put in the declaration? You need to raise hands That's that's kind of disqualification Okay, which is the keyword used to observe property changes on a property Just after it is set to a new value, which is really I'm not going to ask to you Which is basically a new feature in swipe in objective see what you had is Observers or delegates on on the view controller level is just like you had View did load view will disappear. You did disappear. Well, Swift has property observers on on the property label And you can do certain stuff When the value is set to something Let's say you have a label and once you assign certain things to the label You want to change the color of the label or you want to assign a new property to the font you can use these property observers So, but what is the keyword? You know That's correct again Unfortunately, I have only 10% so you can't really Now this is not just for one book you can you can buy any books from the store, so And you I'm going to leave it here just in case anyone There's something missing in this in this code. Yeah, that's great Because when you're overriding a function, right? You're basically need to ensure that the superclass method gets executed properly so you need something like Super That's it for tonight. Thank you I'm going to ask more difficult questions coming But as I mean Talking about the sweep study group, it's going to start from Starting next month and I'll send out the details. I'll probably not use the meetup group to announce it So because then it's going to spam everyone who are not interested in the study group, for example So I'm going to use the Facebook group. If you haven't Just join iOS steps out on Facebook and I will I will announce about the study group This is probably still going to happen here because it's easier for me to organize here And then if it's here, then I can probably try to get sponsorship for food as well I can't promise that at the moment if we do it very regularly I'm also But feel free to hang around for quite a bit. I think it's mine You can wrap up around 9 30 you want to talk to each other Then just feel free to hang around and talk to each other. Thank you all for coming tonight. Thanks