FAQ: Reference Fundamentals - Casting

This community-built FAQ covers the “Casting” exercise from the lesson “Reference Fundamentals”.

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I believe this is a typo but i’m pretty sure it should be written dbk and not bdk

Book bk = new Book();
Dissertation bdk = (Book)bk;

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There is a typo here I believe “In many cases, the downcast will still fail. Here, Book can’t reference a Dissertation object, so when we run explicitly downcast we see that it fails with a new error message:”

It should say “Dissertation can’t reference a Book object”

Book bk = new Book();
Dissertation bdk = (Book)bk;

That’s the code that comes before those words. In that line we are trying to use a Book reference on Dissertation, it’s no typo.
However, my question is how does this make sense? We are casting an object of type Book into Book and trying to save it into Dissertation type?
I would understand if we tried this:

Book bk = new Book();
Dissertation bdk = (Dissertation)bk;

But their example is casting an object of a type Book into a type that it already is… this should be a typo though?
I mean usually when we use cast, we cast into a type we want to convert so:

//everything fine here
int i = (int)numberAsString;

//while this would make no sense and it's obvious it would not work
int i = (string)numberAsString;

Can someone enlighten me plz? :woman_shrugging: