Not sure if this is the best place to ask, but doe...

# javascript

[Big Chungus]

Not sure if this is the best place to ask, but does anyone know what this TS snippet does?

const elm = vnode.elm = oldVnode.elm!

[Big Chungus]

That double assignment confuses me

[turansky]

vnode.elm = oldVnode.elm! // ! in TS = !! in Kotlin
const elm = vnode.elm

[Big Chungus]

OMFG, another page of JS "magic"

[Big Chungus]

Thanks, though

[diesieben07]

! and !! are not quite the same. ! doesn't check anything, it just tells TS to assume its not null

[Big Chungus]

So ! == Any? as Any and !! == not null assertion like in kotlin?

[diesieben07]

No, there is no ! equivalent in Kotlin

[diesieben07]

Any? as Any is basically the same as !!

[diesieben07]

But if you are translating this code, probably go with !!

[turansky]

! - Non-null assertion operator

[diesieben07]

! will never throw an exception, even if the operand is null. !! will

[turansky]

Your truth

[turansky]

// in Kotlin
vnode.elm = oldVnode.elm.unsafeCast<Elm>()
val elm = vnode.elm

[napperley]

Could that code snippet (in the original post) be a example of TS interacting with Elm ( https://elm-lang.org/ )?

[Big Chungus]

No it's a snippet from snabbdom code

[Big Chungus]

Elm stands for html dom element