That’s so much simpler, isn’t it?
Basically, the findViewById() method is still in use. But there’s no need to write it yourself. Kotlin will do it for you.
When you use Android Extensions, the findCachedViewById() function and the HashMap instance will be generated automatically. Every access to your view by its identifier will be replaced with a new function call. If it’s the first time you access the view, this function will call the usual findViewById() function, and will add the received view into the HashMap to retrieve the view from it the next time you access it.