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Welcome back.

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Now we're going to look at unsafe and safe cast operators, and they are useful because sometimes you

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just need to cast something right?

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So you have something in a specific type and you need to cast it in another type.

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And that's where the aski word comes in.

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And this is an unsafe cast operator.

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Sometimes it is not possible to cast a variable and it throws an exception.

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And this is called an unsafe cast.

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The answer, of course, is performed by the infix operator s.

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And let's have a look at an example here.

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A nullable string with a question mark cannot be cast to a nonvolatile string.

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So a string without a question mark because this then throws an exception.

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So let's look at this function, Menhir.

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We have this value object of a type any nullable, which is now and then we have this value string or

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star, which is a type string.

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And what we try to do is we try to cast object, so object as string and then print that string that

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we created.

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So the problem is that we get an error here, an exception to be precise.

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It says exception in thread mean kotlin typecast exception now cannot be cast to non null type in Scotland

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string.

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So here, of course this doesn't work because the object of type any nullable is actually null.

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So it's empty.

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But this frozen arrow, so this really Kresh, our software, our program, and we want to avoid that

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at all cost.

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Right.

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So what can we do?

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Well, let's have a look in a second.

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But first, it generates a class cast exception, trying to cast an integer value of the any type into

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a string type leads to a class cast exception.

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So here we have an object of type any one, two, three, and we try to cast that to a string so we

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save all string or star of type.

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String should be object as string.

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This throws a class cast exception because any could be any typewrite that's just interprets whatever

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data it gets and it interprets in this case that one on 23 is an integer.

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So it's going to say that integer cannot be cast to a string.

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We need to use another approach.

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Right.

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We cannot cast we would need to use type conversion or parsing here.

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All right.

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So now let's look at an example where this actually works.

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So the source and the target variable needs to be knuckleballs for casting to work.

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So here we have the object to any which is of type nullable.

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So we have this question mark and has a string in there.

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So a string is hidden, so to speak, in the any object.

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And then we have a string, which is also a nullable.

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So what we can do is we can say object should be.

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Cast into a string, so it should be a type string nullable, so this will all put the string on safe

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cast.

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There is an operator, however, which makes our life even easier.

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So there is something called Save Cast Operator and there as question mark.

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So the save cast operator provides a save cast operation to safely cast to a type it returns.

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Now, if casting is not possible rather than throwing and cast exception.

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Exception.

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OK, so this is very good because then our program will not crash.

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If it doesn't work, it will just return not.

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All right.

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So here example of save operation.

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So we have a location which is of type any as it actually is a string.

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Right.

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So in the background there's a string and as you can see, it's not nullable any.

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Then we have a safe string, which is a string that is available.

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And what it tries to do, it tries to get the location as a string.

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So it uses the safe cast operation here.

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Then we have a safe int, which is an integer nullable and it tries the same thing.

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So it tries to get the location as an integer.

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But of course, a text cannot be an integer.

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Right.

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Or at least a worse as we see here.

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Kotlin cannot be of type integer, not even integer nullable.

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It will just be not right.

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So the output here is kotlin and no.

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All right.

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Four to save string.

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And now for the safe int because it wasn't able to convert it because Kotlin is not convertible or Casterbridge

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so to speak.

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It's not Costabile into an integer.

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All right, so that's it for unsafe and safe casting operators for now and yeah, further in the course,

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we will use it and then it will make a lot more sense because here the examples, of course, are very

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abstract and they are very purpose driven.

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But later on, we will see how it actually is going to work.

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All right.

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So see you in the next video.