What is as! And what is it for?

Question

iOS

Guys, another question. I decided to use the preparedforSegue method, in which I came across as! , I can not understand what it is for, I would like to understand, thanks in advance

Answer 1

It is the casting (casting) of one data type to another, if so required by the one who takes the value of this type, and if such a cast is itself possible.

Answer 2

In the docks about optional types.. ! - take the value and do not care that it may not be,