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kotlinlang

What’s the correct way to transform a `NSNumber` to `kotlin.Number`? Is it just `myNsNumber as Number`?

<https://kotlinlang.org/docs/native-objc-interop.html#nsnumber>

`NSNumber` can be a `Boolean` while Kotlin `Number` cannot, so `NSNumber` and Kotlin’s `Number` can’t match.

You should probably not use NSNumber, the same way you should probably not use Number in Kotlin

Unfortunately I’m dealing with both `NumberFormatter` and `NSNumberFormatter` which exclusively parse to their respective platform number types

You can probably make extensions to map `NSNumber` to kotlin types, but they aren’t all subtypes of `Number`

I ended up going with

```        checkNotNull((number as? Double) ?: (number as? Long)) {
            "$number is not either a Double or a Long."
        }```

Wouldn’t the first cast always work if it’s not a Boolean?

I would probably use `NSDecimalIsNotANumber` to fail on Booleans and `objCType` to map to the correct Kotlin Number subclass in an extensions

As long as you know your `NSNumber` is not a boolean, `nsNumber as Number` works, as does `kotlinNumber as NSNumber`. Boolean `NSNumber`s will be 0 or 1 though. I've had to handle `NSNumber` boolean values in dictionaries/maps in another explicit format though.